Cybersecurity Updates

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Amazon Dismisses Claims Alexa ‘Skills’ Can Bypass Security Vetting Process
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Stalkerware Volumes Remain Concerningly High, Despite Bans
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Lazarus Targets Defense Companies with ThreatNeedle Malware
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Yeezy Fans Face Sneaker-Bot Armies for Boost ‘Sun’ Release  
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Malware Gangs Partner Up in Double-Punch Security Threat
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Podcast: Ransomware Attacks Exploded in Q4 2020
Researchers said they saw a seven-times increase in ransomware activity in the fourth quarter of 2020, across various families – from Ryuk to Egregor.

Protecting Sensitive Cardholder Data in Today’s Hyper-Connected World
Retailers that lacked significant digital presence pre-COVID are now reaching new audiences through e-commerce sites that are accessible anytime, from anywhere, on any device.

Cyberattacks Launch Against Vietnamese Human-Rights Activists
Vietnam joins the ranks of governments using spyware to crack down on human-rights defenders.

Health Website Leaks 8 Million COVID-19 Test Results
A teenaged ethical hacker discovered a flawed endpoint associated with a health-department website in the state of Bengal, which exposed personally identifiable information related to test results.

Malicious Mozilla Firefox Extension Allows Gmail Takeover
The malicious extension, FriarFox, snoops in on both Firefox and Gmail-related data.

The SolarWinds Body Count Now Includes NASA and the FAA
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Clubhouse's Security and Privacy Lag Behind Its Huge Growth
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Hackers Tied to Russia's GRU Targeted the US Grid for Years
A Sandworm-adjacent group has successfully breached US critical infrastructure a handful of times, according to new findings from the security firm Dragos.

2034, Part V: Sailing Into Darkness
“Somewhere in that black hole was the Chinese fleet. She would be expected to find and destroy it.”

The Woman Bulldozing Video Games’ Toughest DRM
For Empress, cracking titles like Red Dead Redemption 2 and Immortals Fenyx Rising is more than a pastime. It's a mission.

China Hijacked an NSA Hacking Tool—and Used It for Years
The hackers used the agency’s EpMe exploit to attack Windows devices years before the Shadow Brokers leaked the agency’s zero-day arsenal online.

A Trippy Visualization Charts the Internet's Growth
In 2003, Barrett Lyon created a map of the internet. In 2021, he did it again—and showed just how quickly it's expanded.

Sites Have a Sneaky New Way to Track You Across the Web
Plus: A LastPass rate change, Clubhouse concerns, and more of the week's top security news.

Apple Offers Its Closest Look Yet at iOS and MacOS Security
In its latest Platform Security Guide, Cupertino raised the curtain on the critical features that protect against hackers.

Feds Indict North Korean Hackers for Years of Heists
The three men are allegedly part of a group that tried to steal $1.3 billion in an extended—and ongoing—cybercrime spree.

Parler Says It’s Back
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Malware Is Now Targeting Apple’s New M1 Processor
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How to Avoid Phishing Emails and Scams
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2034, Part IV: The Spratly Islands Ambush
“In a thousand years America won’t be remembered as a country, but simply as a fleeting moment.”

France Ties Russia's Sandworm to a Multiyear Hacking Spree
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The Untold History of America’s Zero-Day Market
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A Billion-Dollar Dark Web Crime Lord Calls It Quits
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A Barcode Scanner App With Millions of Downloads Goes Rogue
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Cyberpunk 2077 Maker Was Hit With Ransomware—and Won't Pay Up
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AA21-055A: Exploitation of Accellion File Transfer Appliance
Original release date: February 24, 2021 | Last revised: February 25, 2021

Summary

This joint advisory is the result of a collaborative effort by the cybersecurity authorities of Australia,[1] New Zealand,[2] Singapore,[3] the United Kingdom,[4] and the United States.[5][6] These authorities are aware of cyber actors exploiting vulnerabilities in Accellion File Transfer Appliance (FTA).[7] This activity has impacted organizations globally, including those in Australia, New Zealand, Singapore, the United Kingdom, and the United States.

Worldwide, actors have exploited the vulnerabilities to attack multiple federal and state, local, tribal, and territorial (SLTT) government organizations as well as private industry organizations including those in the medical, legal, telecommunications, finance, and energy sectors. According to Accellion, this activity involves attackers leveraging four vulnerabilities to target FTA customers.[8] In one incident, an attack on an SLTT organization potentially included the breach of confidential organizational data. In some instances observed, the attacker has subsequently extorted money from victim organizations to prevent public release of information exfiltrated from the Accellion appliance.

This Joint Cybersecurity Advisory provides indicators of compromise (IOCs) and recommended mitigations for this malicious activity. For a downloadable copy of IOCs, see: AA21-055A.stix and MAR-10325064-1.v1.stix.

Click here for a PDF version of this report.

Technical Details

Accellion FTA is a file transfer application that is used to share files. In mid-December 2020, Accellion was made aware of a zero-day vulnerability in Accellion FTA and released a patch on December 23, 2020. Since then, Accellion has identified cyber actors targeting FTA customers by leveraging the following additional vulnerabilities.

• CVE-2021-27101 – Structured Query Language (SQL) injection via a crafted HOST header (affects FTA 9_12_370 and earlier)
• CVE-2021-27102 – Operating system command execution via a local web service call (affects FTA versions 9_12_411 and earlier)
• CVE-2021-27103 – Server-side request forgery via a crafted POST request (affects FTA 9_12_411 and earlier)
• CVE-2021-27104 – Operating system command execution via a crafted POST request (affects FTA 9_12_370 and earlier)

One of the exploited vulnerabilities (CVE-2021-27101) is an SQL injection vulnerability that allows an unauthenticated user to run remote commands on targeted devices. Actors have exploited this vulnerability to deploy a webshell on compromised systems. The webshell is located on the target system in the file /home/httpd/html/about.html or /home/seos/courier/about.html. The webshell allows the attacker to send commands to targeted devices, exfiltrate data, and clean up logs. The clean-up functionality of the webshell helps evade detection and analysis during post incident response. The Apache /var/opt/cache/rewrite.log file may also contain the following evidence of compromise:

• [.'))union(select(c_value)from(t_global)where(t_global.c_param)=('w1'))] (1) pass through /courier/document_root.html
• [.'))union(select(reverse(c_value))from(t_global)where(t_global.c_param)=('w1'))] (1) pass through /courier/document_root.html
• ['))union(select(loc_id)from(net1.servers)where(proximity)=(0))] (1) pass through /courier/document_root.html

These entries are followed shortly by a pass-through request to sftp_account_edit.php. The entries are the SQL injection attempt indicating an attempt at exploitation of the HTTP header parameter HTTP_HOST.

Apache access logging shows successful file listings and file exfiltration:

• “GET /courier/about.html?aid=1000 HTTP/1.1” 200 {Response size}
• “GET /courier/about.htmldwn={Encrypted Path}&fn={encrypted file name} HTTP/1.1” 200 {Response size}

When the clean-up function is run, it modifies archived Apache access logs /var/opt/apache/c1s1-access_log.*.gz and replaces the file contents with the following string:

      Binary file (standard input) matches

In two incidents, the Cybersecurity and Infrastructure Security Agency (CISA) observed a large amount of data transferred over port 443 from federal agency IP addresses to 194.88.104[.]24. In one incident, the Cyber Security Agency of Singapore observed multiple TCP sessions with IP address 45.135.229[.]179.

Organizations are encouraged to investigate the IOCs outlined in this advisory and in AR21-055A. If an Accellion FTA appears compromised, organizations can get an indication of the exfiltrated files by obtaining a list of file-last-accessed events for the target files of the symlinks located in the /home/seos/apps/1000/ folder over the period of malicious activity. This information is only indicative and may not be a comprehensive identifier of all exfiltrated files.

Mitigations

Organizations with Accellion FTA should:

• Temporarily isolate or block internet access to and from systems hosting the software.
• Assess the system for evidence of malicious activity including the IOCs, and obtain a snapshot or forensic disk image of the system for subsequent investigation.
• If malicious activity is identified, obtain a snapshot or forensic disk image of the system for subsequent investigation, then:
  • Consider conducting an audit of Accellion FTA user accounts for any unauthorized changes, and consider resetting user passwords.
  • Reset any security tokens on the system, including the “W1” encryption token, which may have been exposed through SQL injection.
• Update Accellion FTA to version FTA_9_12_432 or later.
• Evaluate potential solutions for migration to a supported file-sharing platform after completing appropriate testing.
  • Accellion has announced that FTA will reach end-of-life (EOL) on April 30, 2021.[9] Replacing software and firmware/hardware before it reaches EOL significantly reduces risks and costs.

Additional general best practices include:

• Deploying automated software update tools to ensure that third-party software on all systems is running the most recent security updates provided by the software vendor.
• Only using up-to-date and trusted third-party components for the software developed by the organization.
• Adding additional security controls to prevent the access from unauthenticated sources.

Resources

• FireEye Blog – Cyber Criminals Exploit Accellion FTA for Data Theft and Extortion 
  • https://www.fireeye.com/blog/threat-research/2021/02/accellion-fta-exploited-for-data-theft-and-extortion.html 
• Center for Internet Security (CIS) Critical Security Controls for Effective Cyber Defense, known as "CIS Controls" 
  • https://www.cisecurity.org/controls/
  • https://www.cisecurity.org/ms-isac/
• Australia, Canada, New Zealand, the United Kingdom, and the United States Joint Advisory on Technical Approaches to Uncovering and Remediating Malicious Activity 
  • https://us-cert.cisa.gov/ncas/alerts/aa20-245a 
• CISA and MS-ISAC’s Ransomware Guide 
  • https://www.cisa.gov/sites/default/files/publications/CISA_MS-ISAC_Ransomware%20Guide_S508C.pdf

References

• [1] Australian Cyber Security Centre (ACSC)
• [2] New Zealand National Cyber Security Centre (NZ NCSC)
• [3] Singapore Cyber Security Agency (CSA)
• [4] United Kingdom National Cyber Security Centre (UK NCSC)
• [5] United States Cybersecurity and Infrastructure Security Agency (CISA)
• [6] United States Multi-State Information Sharing and Analysis Center (MS-ISAC)
• [7] Accellion Press Release: Update to Recent FTA Security Incident
• [8] Accellion Press Release: Update to Recent FTA Security Incident
• [9] Accellion Announcement: End-of-Life for Legacy FTA Software

Revisions

• February 24, 2021: Initial Version

AA21-048A: AppleJeus: Analysis of North Korea’s Cryptocurrency Malware
Original release date: February 17, 2021 | Last revised: February 18, 2021

Summary

This Advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework. See the ATT&CK for Enterprise for all referenced threat actor tactics and techniques.

This joint advisory is the result of analytic efforts among the Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), and the Department of Treasury (Treasury) to highlight the cyber threat to cryptocurrency posed by North Korea, formally known as the Democratic People’s Republic of Korea (DPRK), and provide mitigation recommendations. Working with U.S. government partners, FBI, CISA, and Treasury assess that Lazarus Group—which these agencies attribute to North Korean state-sponsored advanced persistent threat (APT) actors—is targeting individuals and companies, including cryptocurrency exchanges and financial service companies, through the dissemination of cryptocurrency trading applications that have been modified to include malware that facilitates theft of cryptocurrency.

These cyber actors have targeted organizations for cryptocurrency theft in over 30 countries during the past year alone. It is likely that these actors view modified cryptocurrency trading applications as a means to circumvent international sanctions on North Korea—the applications enable them to gain entry into companies that conduct cryptocurrency transactions and steal cryptocurrency from victim accounts. As highlighted in FASTCash 2.0: North Korea's BeagleBoyz Robbing Banks and Guidance on the North Korean Cyber Threat, North Korea’s state-sponsored cyber actors are targeting cryptocurrency exchanges and accounts to steal and launder hundreds of millions of dollars in cryptocurrency.[1][2][3] The U.S. Government refers to malicious cyber activity by the North Korean government as HIDDEN COBRA. For more information on HIDDEN COBRA activity, visit https://www.us-cert.cisa.gov/northkorea.

The U.S. Government has identified malware and indicators of compromise (IOCs) used by the North Korean government to facilitate cryptocurrency thefts; the cybersecurity community refers to this activity as “AppleJeus.” This report catalogues AppleJeus malware in detail. North Korea has used AppleJeus malware posing as cryptocurrency trading platforms since at least 2018. In most instances, the malicious application—seen on both Windows and Mac operating systems—appears to be from a legitimate cryptocurrency trading company, thus fooling individuals into downloading it as a third-party application from a website that seems legitimate. In addition to infecting victims through legitimate-looking websites, HIDDEN COBRA actors also use phishing, social networking, and social engineering techniques to lure users into downloading the malware.

Refer to the following Malware Analysis Reports (MARs) for full technical details of AppleJeus malware and associated IOCs.

• MAR-10322463-1.v1: AppleJeus – Celas Trade Pro
• MAR-10322463-2.v1: AppleJeus – JMT Trading
• MAR-10322463-3.v1: AppleJeus – Union Crypto
• MAR-10322463-4.v1: AppleJeus – Kupay Wallet
• MAR-10322463-5.v1: AppleJeus – CoinGoTrade
• MAR-10322463-6.v1: AppleJeus – Dorusio
• MAR-10322463-7.v1: AppleJeus – Ants2Whale

Click here for a PDF version of this report.

Technical Details

The North Korean government has used multiple versions of AppleJeus since the malware was initially discovered in 2018. This section outlines seven of the versions below. The MARs listed above provide further technical details of these versions. Initially, HIDDEN COBRA actors used websites that appeared to host legitimate cryptocurrency trading platforms to infect victims with AppleJeus; however, these actors are now also using other initial infection vectors, such as phishing, social networking, and social engineering techniques, to get users to download the malware.

Targeted Nations

HIDDEN COBRA actors have targeted institutions with AppleJeus malware in several sectors, including energy, finance, government, industry, technology, and telecommunications. Since January 2020, the threat actors have targeted these sectors in the following countries: Argentina, Australia, Belgium, Brazil, Canada, China, Denmark, Estonia, Germany, Hong Kong, Hungary, India, Ireland, Israel, Italy, Japan, Luxembourg, Malta, the Netherlands, New Zealand, Poland, Russia, Saudi Arabia, Singapore, Slovenia, South Korea, Spain, Sweden, Turkey, the United Kingdom, Ukraine, and the United States (figure 1).

 
Figure 1: Countries targeted with AppleJeus by HIDDEN COBRA threat actors since 2020

AppleJeus Versions Note

The version numbers used for headings in this document correspond to the order the AppleJeus campaigns were identified in open source or through other investigative means. These versions may or may not be in the correct order to develop or deploy the AppleJeus campaigns.

AppleJeus Version 1: Celas Trade Pro

Introduction and Infrastructure

In August 2018, open-source reporting disclosed information about a trojanized version of a legitimate cryptocurrency trading application on an undisclosed victim’s computer. The malicious program, known as Celas Trade Pro, was a modified version of the benign Q.T. Bitcoin Trader application. This incident led to the victim company being infected with a Remote Administration Tool (RAT) known as FALLCHILL, which was attributed to North Korea (HIDDEN COBRA) by the U.S. Government. FALLCHILL is a fully functional RAT with multiple commands that the adversary can issue from a command and control (C2) server to infected systems via various proxies. FALLCHILL typically infects a system as a file dropped by other HIDDEN COBRA malware (Develop Capabilities: Malware [T1587.001]). Because of this, additional HIDDEN COBRA malware may be present on systems compromised with FALLCHILL.[4]

Further research revealed that a phishing email from a Celas LLC company (Phishing: Spearphishing Link [T1566.002]) recommended the trojanized cryptocurrency trading application to victims. The email provided a link to the Celas’ website, celasllc[.]com (Acquire Infrastructure: Domain [T1583.001]), where the victim could download a Windows or macOS version of the trojanized application.

The celasllc[.]com domain resolved to the following Internet Protocol (IP) addresses from May 29, 2018, to January 23, 2021.

• 45.199.63[.]220
• 107.187.66[.]103
• 145.249.106[.]19
• 175.29.32[.]160
• 185.142.236[.]213
• 185.181.104[.]82
• 198.251.83[.]27
• 208.91.197[.]46
• 209.99.64[.]18

The celasllc[.]com domain had a valid Sectigo (previously known as Comodo) Secure Sockets Layer (SSL) certificate (Obtain Capabilities: Digital Certificates [T1588.004]). The SSL certificate was “Domain Control Validated,” a weak security verification level that does not require validation of the owner’s identity or the actual business’s existence.

Celas Trade Pro Application Analysis

Windows Program

The Windows version of the malicious Celas Trade Pro application is an MSI Installer (.msi). The MSI Installer installation package comprises a software component and an application programming interface (API) that Microsoft uses for the installation, maintenance, and removal of software. The installer looks legitimate and is signed by a valid Sectigo certificate that was purchased by the same user as the SSL certificate for celasllc[.]com (Obtain Capabilities: Code Signing Certificates [T1588.003]). The MSI Installer asks the victim for administrative privileges to run (User Execution: Malicious File [T1204.002]).

Once permission is granted, the threat actor is able to run the program with elevated privileges (Abuse Elevation Control Mechanism [T1548]) and MSI executes the following actions.

• Installs CelasTradePro.exe in folder C:\Program Files (x86)\CelasTradePro
• Installs Updater.exe in folder C:\Program Files (x86)\CelasTradePro
• Runs Updater.exe with the CheckUpdate parameters

The CelasTradePro.exe program asks for the user’s exchange and loads a legitimate-looking cryptocurrency trading platform—very similar to the benign Q.T. Bitcoin Trader—that exhibits no signs of malicious activity.

The Updater.exe program has the same program icon as CelasTradePro.exe. When run, it checks for the CheckUpdate parameter, collects the victim’s host information (System Owner/User Discovery [T1033]), encrypts the collected information with a hardcoded XOR encryption, and sends information to a C2 website (Exfiltration Over C2 Channel [T1041]).

macOS X Program

The macOS version of the malicious application is a DMG Installer that has a disk image format that Apple commonly uses to distribute software over the internet. The installer looks legitimate and has a valid digital signature from Sectigo (Obtain Capabilities: Digital Certificates [T1588.004]). It has very similar functionality to the Windows version. The installer executes the following actions.

• Installs CelasTradePro in folder /Applications/CelasTradePro.app/Contents/MacOS/
• Installs Updater in folder /Applications/CelasTradePro.app/Contents/MacOS
• Executes a postinstall script
  • Moves .com.celastradepro.plist to folder LaunchDaemons
  • Runs Updater with the CheckUpdate parameter

CelasTradePro asks for the user’s exchange and loads a legitimate-looking cryptocurrency trading platform—very similar to the benign Q.T. Bitcoin Trader—that exhibits no signs of malicious activity.

Updater checks for the CheckUpdate parameter and, when found, it collects the victim’s host information (System Owner/User Discovery [T1033]), encrypts the collected information with a hardcoded XOR key before exfiltration, and sends the encrypted information to a C2 website (Exfiltration Over C2 Channel [T1041]). This process helps the adversary obtain persistence on a victim’s network.

The postinstall script is a sequence of instructions that runs after successfully installing an application (Command and Scripting Interpreter: AppleScript [T1059.002]). This script moves property list (plist) file .com.celastradepro.plist from the installer package to the LaunchDaemons folder (Scheduled Task/Job: Launchd [T1053.004]). The leading “.” makes it unlisted in the Finder app or default Terminal directory listing (Hide Artifacts: Hidden Files and Directories [T1564.001]). Once in the folder, this property list (plist) file will launch the Updater program with the CheckUpdate parameter on system load as Root for every user. Because the LaunchDaemon will not run automatically after the plist file is moved, the postinstall script launches the Updater program with the CheckUpdate parameter and runs it in the background (Create or Modify System Process: Launch Daemon [T1543.004]).

Payload

After a cybersecurity company published a report detailing the above programs and their malicious extras, the website was no longer accessible. Since this site was the C2 server, the payload cannot be confirmed. The cybersecurity company that published the report states the payload was an encrypted and obfuscated binary (Obfuscated Files or Information [T1027]), which eventually drops FALLCHILL onto the machine and installs it as a service (Create or Modify System Process: Windows Service [T1543.003]). FALLCHILL malware uses an RC4 encryption algorithm with a 16-byte key to protect its communications (Encrypted Channel: Symmetric Cryptography [T1573.001]). The key employed in these versions has also been used in a previous version of FALLCHILL.[5][6]

For more details on AppleJeus Version 1: Celas Trade Pro, see MAR-10322463-1.v1.

AppleJeus Version 2: JMT Trading

Introduction and Infrastructure

In October 2019, a cybersecurity company identified a new version of the AppleJeus malware—JMT Trading—thanks to its many similarities to the original AppleJeus malware. Again, the malware was in the form of a cryptocurrency trading application, which a legitimate-looking company, called JMT Trading, marketed and distributed on their website, jmttrading[.]org (Acquire Infrastructure: Domain [T1583.001]). This website contained a “Download from GitHub” button, which linked to JMT Trading’s GitHub page (Acquire Infrastructure: Web Services [T1583.006]), where Windows and macOS X versions of the JMT Trader application were available for download (Develop Capabilities: Malware [T1587.001]). The GitHub page also included .zip and tar.gz files containing the source code.

The jmttrading[.]org domain resolved to the following IP addresses from October 15, 2016, to January 22, 2021.

• 45.33.2[.]79
• 45.33.23[.]183
• 45.56.79[.]23
• 45.79.19[.]196
• 96.126.123[.]244
• 146.112.61[.]107
• 184.168.221[.]40
• 184.168.221[.]57
• 198.187.29[.]20
• 198.54.117[.]197
• 198.54.117[.]198
• 198.54.117[.]199
• 198.54.117[.]200
• 198.58.118[.]167

The jmttrading[.]org domain had a valid Sectigo SSL certificate (Obtain Capabilities: Digital Certificates [T1588.004]). The SSL certificate was “Domain Control Validated,” a weak security verification level that does not require validation of the owner’s identity or the actual business’s existence. The current SSL certificate was issued by Let’s Encrypt.

JMT Trading Application Analysis

Windows Program

The Windows version of the malicious cryptocurrency application is an MSI Installer. The installer looks legitimate and has a valid digital signature from Sectigo (Obtain Capabilities: Digital Certificates [T1588.004]). The signature was signed with a code signing certificate purchased by the same user as the SSL certificate for jmttrading[.]org (Obtain Capabilities: Code Signing Certificates [T1588.003]). The MSI Installer asks the victim for administrative privileges to run (User Execution: Malicious File [T1204.002]).

Once permission is granted, the MSI executes the following actions.

• Installs JMTTrader.exe in folder C:\Program Files (x86)\JMTTrader
• Installs CrashReporter.exe in folder C:\Users\<username>\AppData\Roaming\JMTTrader
• Runs CrashReporter.exe with the Maintain parameter

The JMTTrader.exe program asks for the user’s exchange and loads a legitimate-looking cryptocurrency trading platform—very similar to CelasTradePro.exe and the benign Q.T. Bitcoin Trader—that exhibits no signs of malicious activity.

The program CrashReporter.exe is heavily obfuscated with the ADVObfuscation library, renamed “snowman” (Obfuscated Files or Information [T1027]). When run, it checks for the Maintain parameter and collects the victim’s host information (System Owner/User Discovery [T1033]), encrypts the collected information with a hardcoded XOR key before exfiltration, and sends the encrypted information to a C2 website (Exfiltration Over C2 Channel [T1041]). The program also creates a scheduled SYSTEM task, named JMTCrashReporter, which runs CrashReporter.exe with the Maintain parameter at any user’s login (Scheduled Task/Job: Scheduled Task [T1053.005]).

macOS X Program

The macOS version of the malicious application is a DMG Installer. The installer looks legitimate and has very similar functionality to the Windows version, but it does not have a digital certificate and will warn the user of that before installation. The installer executes the following actions.

• Installs JMTTrader in folder /Applications/JMTTrader.app/Contents/MacOS/
• Installs .CrashReporter in folder /Applications/JMTTrader.app/Contents/Resources/
  • Note: the leading “.” makes it unlisted in the Finder app or default Terminal directory listing.
• Executes a postinstall script
  • Moves .com.jmttrading.plist to folder LaunchDaemons
  • Changes the file permissions on the plist
  • Runs CrashReporter with the Maintain parameter
  • Moves .CrashReporter to folder /Library/JMTTrader/CrashReporter
  • Makes .CrashReporter executable

The JMTTrader program asks for the user’s exchange and loads a legitimate-looking cryptocurrency trading platform—very similar to CelasTradePro and the benign Q.T. Bitcoin Trader—that exhibits no signs of malicious activity.

The CrashReporter program checks for the Maintain parameter and is not obfuscated. This lack of obfuscation makes it easier to determine the program’s functionality in detail. When it finds the Maintain parameter, it collects the victim’s host information (System Owner/User Discovery [T1033]), encrypts the collected information with a hardcoded XOR key before exfiltration, and sends the encrypted information to a C2 website (Exfiltration Over C2 Channel [T1041]).

The postinstall script has similar functionality to the one used by CelasTradePro, but it has a few additional features (Command and Scripting Interpreter: AppleScript [T1059.002]). It moves the property list (plist) file .com.jmttrading.plist from the Installer package to the LaunchDaemons folder (Scheduled Task/Job: Launchd [T1053.004]), but also changes the file permissions on the plist file. Once in the folder, this property list (plist) file will launch the CrashReporter program with the Maintain parameter on system load as Root for every user. Also, the postinstall script moves the .CrashReporter program to a new location /Library/JMTTrader/CrashReporter and makes it executable. Because the LaunchDaemon will not run automatically after the plist file is moved, the postinstall script launches CrashReporter with the Maintain parameter and runs it in the background (Create or Modify System Process: Launch Daemon [T1543.004]).

Payload

Soon after the cybersecurity company tweeted about JMT Trader on October 11, 2019, the files on GitHub were updated to clean, non-malicious installers. Then on October 13, 2019, a different cybersecurity company published an article detailing the macOS X JMT Trader, and soon after, the C2 beastgoc[.]com website went offline. There is not a confirmed sample of the payload to analyze at this point.

For more details on AppleJeus Version 2: JMT Trading, see MAR-10322463-2.v1.

AppleJeus Version 3: Union Crypto

Introduction and Infrastructure

In December 2019, another version of the AppleJeus malware was identified on Twitter by a cybersecurity company based on many similarities to the original AppleJeus malware. Again, the malware was in the form of a cryptocurrency trading application, which was marketed and distributed by a legitimate-looking company, called Union Crypto, on their website, unioncrypto[.]vip (Acquire Infrastructure: Domain [T1583.001]). Although this website is no longer available, a cybersecurity researcher discovered a download link, https://www.unioncrypto[.]vip/download/W6c2dq8By7luMhCmya2v97YeN, recorded on VirusTotal for the macOS X version of UnionCryptoTrader. In contrast, open-source reporting stated that the Windows version might have been downloaded via instant messaging service Telegram, as it was found in a “Telegram Downloads” folder on an unnamed victim.[7]

The unioncrypto[.]vip domain resolved to the following IP addresses from June 5, 2019, to July 15, 2020.

• 104.168.167[.]16
• 198.54.117[.]197
• 198.54.117[.]198
• 198.54.117[.]199
• 198.54.117[.]200

The domain unioncrypto[.]vip had a valid Sectigo SSL certificate (Obtain Capabilities: Digital Certificates [T1588.004]). The SSL certificate was “Domain Control Validated,” a weak security verification level that does not require validation of the owner’s identity or the actual business’s existence.

Union Crypto Trader Application Analysis

Windows Program

The Windows version of the malicious cryptocurrency application is a Windows executable (.exe) (User Execution: Malicious File [T1204.002]), which acts as an installer that extracts a temporary MSI Installer.

The Windows program executes the following actions.

• Extracts UnionCryptoTrader.msi to folder C:\Users\<username>\AppData\Local\Temp\{82E4B719-90F74BD1-9CF1-56CD777E0C42}
• Runs UnionCryptoUpdater.msi
  • Installs UnionCryptoTrader.exe in folder C:\Program Files\UnionCryptoTrader
  • Installs UnionCryptoUpdater.exe in folder C:\Users\<username>\AppData\Local\UnionCryptoTrader
• Deletes UnionCryptoUpdater.msi
• Runs UnionCryptoUpdater.exe

The program UnionCryptoTrader.exe loads a legitimate-looking cryptocurrency arbitrage application—defined as “the simultaneous buying and selling of securities, currency, or commodities in different markets or in derivative forms to take advantage of differing prices for the same asset”—which exhibits no signs of malicious activity. This application is very similar to another cryptocurrency arbitrage application known as Blackbird Bitcoin Arbitrage.[8]

The program UnionCryptoUpdater.exe first installs itself as a service (Create or Modify System Process: Windows Service [T1543.003]), which will automatically start when any user logs on (Boot or Logon Autostart Execution [T1547]). The service is installed with a description stating it “Automatically installs updates for Union Crypto Trader.” When launched, it collects the victim’s host information (System Owner/User Discovery [T1033]), combines the information in a string that is MD5 hashed and stored in the auth_signature variable before exfiltration, and sends it to a C2 website (Exfiltration Over C2 Channel [T1041]).

macOS X Program

The macOS version of the malicious application is a DMG Installer. The installer looks legitimate and has very similar functionality to the Windows version, but it does not have a digital certificate and will warn the user of that before installation. The installer executes the following actions.

• Installs UnionCryptoTrader in folder /Applications/UnionCryptoTrader.app/Contents/MacOS/
• Installs .unioncryptoupdater in folder /Applications/UnionCryptoTrader.app/Contents/Resources/
  • Note: the leading “.” makes it unlisted in the Finder app or default Terminal directory listing
• Executes a postinstall script
  • Moves .vip.unioncrypto.plist to folder LaunchDaemons
  • Changes the file permissions on the plist to Root
  • Runs unioncryptoupdater
  • Moves .unioncryptoupdater to folder /Library/UnionCrypto/unioncryptoupdater
  • Makes .unioncryptoupdater executable

The UnionCryptoTrader program loads a legitimate-looking cryptocurrency arbitrage application, which exhibits no signs of malicious activity. The application is very similar to another cryptocurrency arbitrage application known as Blackbird Bitcoin Arbitrage.

The .unioncryptoupdater program is signed ad-hoc, meaning it is not signed with a valid code-signing identity. When launched, it collects the victim’s host information (System Owner/User Discovery [T1033]), combines the information in a string that is MD5 hashed and stored in the auth_signature variable before exfiltration, and sends it to a C2 website (Exfiltration Over C2 Channel [T1041]).

The postinstall script has similar functionality to the one used by JMT Trading (Command and Scripting Interpreter: AppleScript [T1059.002]). It moves the property list (plist) file .vip.unioncrypto.plist from the Installer package to the LaunchDaemons folder (Scheduled Task/Job: Launchd [T1053.004]), but also changes the file permissions on the plist file to Root. Once in the folder, this property list (plist) file will launch the .unioncryptoupdater on system load as Root for every user. The postinstall script moves the .unioncryptoupdater program to a new location /Library/UnionCrypto/unioncryptoupdater and makes it executable. Because the LaunchDaemon will not run automatically after the plist file is moved, the postinstall script launches .unioncryptoupdater and runs it in the background (Create or Modify System Process: Launch Daemon [T1543.004]).

Payload

The payload for the Windows malware is a Windows Dynamic-Link-Library. UnionCryptoUpdater.exe does not immediately download the stage 2 malware but instead downloads it after a time specified by the C2 server. This delay could be implemented to prevent researchers from directly obtaining the stage 2 malware.

The macOS X malware’s payload could not be downloaded, as the C2 server is no longer accessible. Additionally, none of the open-source reporting for this sample contained copies of the macOS X payload. The macOS X payload is likely similar in functionality to the Windows stage 2 detailed above.

For more details on AppleJeus Version 3: Union Crypto, see MAR-10322463-3.v1.

Commonalities between Celas Trade Pro, JMT Trading, and Union Crypto

Hardcoded Values

In each AppleJeus version, there are hardcoded values used for encryption or to create a signature when combined with the time (table 1).

Table 1: AppleJeus hardcoded values and uses

The Union Crypto Trader and Celas LLC (XOR) values are 16 bytes in length. For JMT Trader, the first 16 bytes of the Windows and macOS X values are identical, and the additional bytes are in a time format for the Windows sample. The structure of a 16-byte value combined with the time is also used in Union Crypto Trader to create the auth_signature.

As mentioned, FALLCHILL was reported as the final payload for Celas Trade Pro. All FALLCHILL samples use 16-byte hardcoded RC4 keys for sending data, similar to the 16-byte keys in the AppleJeus samples.

Open-Source Cryptocurrency Applications

All three AppleJeus samples are bundled with modified copies of legitimate cryptocurrency applications and can be used as originally designed to trade cryptocurrency. Both Celas LLC and JMT Trader modified the same cryptocurrency application, Q.T. Bitcoin Trader; Union Crypto Trader modified the Blackbird Bitcoin Arbitrage application.

Postinstall Scripts, Property List Files, and LaunchDaemons

The macOS X samples of all three AppleJeus versions contain postinstall scripts with similar logic. The Celas LLC postinstall script only moves the plist file to a new location and launches Updater with the CheckUpdate parameter in the background. The JMT Trader and Union Crypto Trader also perform these actions and have identical functionality. The additional actions performed by both postinstall scripts are to change the file permissions on the plist, make a new directory in the /Library folder, move CrashReporter or UnionCryptoUpdater to the newly created folder, and make them executable.

The plist files for all three AppleJeus files have identical functionality. They only differ in the files’ names and one default comment that was not removed from the Celas LLC plist. As the logic and functionality of the postinstall scripts and plist files are almost identical, the LaunchDaemons created also function the same.

They will all launch the secondary executable as Root on system load for every user.

AppleJeus Version 4: Kupay Wallet

Introduction and Infrastructure

On March 13, 2020, a new version of the AppleJeus malware was identified. The malware was marketed and distributed by a legitimate-looking company, called Kupay Wallet, on their website kupaywallet[.]com (Acquire Infrastructure: Domain [T1583.001]).

The domain www.kupaywallet[.]com resolved to IP address 104.200.67[.]96 from March 20, 2020, to January 16, 2021. CrownCloud US, LLC controlled the IP address (autonomous system number [ASN] 8100), and is located in New York, NY.

The domain www.kupaywallet[.]com had a valid Sectigo SSL certificate (Obtain Capabilities: Digital Certificates [T1588.004]). The SSL certificate was “Domain Control Validated,” a weak security verification level that does not require validation of the owner’s identity or the actual business’s existence.

Kupay Wallet Application Analysis

Windows Program

The Windows version of the malicious cryptocurrency application is an MSI Installer. The MSI executes the following actions.

• Installs Kupay.exe in folder C:\Program Files (x86)\Kupay
• Installs KupayUpgrade.exe in folder C:\Users\<username>\AppData\Roaming\KupaySupport
• Runs KupayUpgrade.exe

The program Kupay.exe loads a legitimate-looking cryptocurrency wallet platform, which exhibits no signs of malicious activity and is very similar to an open-source platform known as Copay, distributed by Atlanta-based company BitPay.

The program KupayUpgrade.exe first installs itself as a service (Create or Modify System Process: Windows Service [T1543.003]), which will automatically start when any user logs on (Boot or Logon Autostart Execution [T1547]). The service is installed with a description stating it is an “Automatic Kupay Upgrade.” When launched, it collects the victim’s host information (System Owner/User Discovery [T1033]), combines the information in strings before exfiltration, and sends it to a C2 website (Exfiltration Over C2 Channel [T1041]).

macOS X Program

The macOS version of the malicious application is a DMG Installer. The installer looks legitimate and has very similar functionality to the Windows version, but it does not have a digital certificate and will warn the user of that before installation. The installer executes the following actions.

• Installs Kupay in folder /Applications/Kupay.app/Contents/MacOS/
• Installs kupay_upgrade in folder /Applications/Kupay.app/Contents/MacOS/
• Executes a postinstall script
  • Creates KupayDaemon folder in /Library/Application Support folder
  • Moves kupay_upgrade to the new folder
  • Moves com.kupay.pkg.wallet.plist to folder /Library/LaunchDaemons/
  • Runs the command launchctl load to load the plist without a restart
  • Runs kupay_upgrade in the background

Kupay is likely a copy of an open-source cryptocurrency wallet application, loads a legitimate-looking wallet program (fully functional), and its functionality is identical to the Windows Kupay.exe program.

The kupay_upgrade program calls its function CheckUpdate (which contains most of the logic functionality of the malware) and sends a POST to the C2 server with a connection named “Kupay Wallet 9.0.1 (Check Update Osx)” (Application Layer Protocol: Web Protocols [T1071.001]). If the C2 server returns a file, it is decoded and written to the victim’s folder /private/tmp/kupay_update with permissions set by the command chmod 700 (only the user can read, write, and execute) (Command and Scripting Interpreter [T1059]). Stage 2 is then launched, and the malware, kupay_upgrade, returns to sleeping and checking in with the C2 server at predetermined intervals (Application Layer Protocol: Web Protocols [T1071.001]).

The postinstall script has similar functionality to other AppleJeus scripts (Command and Scripting Interpreter: AppleScript [T1059.002]). It creates the KupayDaemon folder in /Library/Application Support folder and then moves kupay_upgrade to the new folder. It moves the property list (plist) file com.kupay.pkg.wallet.plist from the Installer package to the /Library/LaunchDaemons/ folder (Scheduled Task/Job: Launchd [T1053.004]). The script runs the command launchctl load to load the plist without a restart (Command and Scripting Interpreter [T1059]). But, since the LaunchDaemon will not run automatically after the plist file is moved, the postinstall script launches kupay_upgrade and runs it in the background (Create or Modify System Process: Launch Daemon [T1543.004]).

Payload

The Windows malware’s payload could not be downloaded since the C2 server is no longer accessible. Additionally, none of the open-source reporting for this sample contained copies of the payload. The Windows payload is likely similar in functionality to the macOS X stage 2 detailed below.

The stage 2 payload for the macOS X malware was decoded and analyzed. The stage 2 malware has a variety of functionalities. Most importantly, it checks in with a C2 and, after connecting to the C2, can send or receive a payload, read and write files, execute commands via the terminal, etc.

For more details on AppleJeus Version 4: Kupay Wallet, see MAR-10322463-4.v1.

AppleJeus Version 5: CoinGoTrade

Introduction and Infrastructure

In early 2020, another version of the AppleJeus malware was identified. This time the malware was marketed and distributed by a legitimate-looking company called CoinGoTrade on their website coingotrade[.]com (Acquire Infrastructure: Domain [T1583.001]).

The domain CoinGoTrade[.]com resolved to IP address 198.54.114[.]175 from February 28, 2020, to January 23, 2021. The IP address is controlled by NameCheap Inc. (ASN 22612) and is located in Atlanta, GA. This IP address is in the same ASN for Dorusio[.]com and Ants2Whale[.]com.

The domain CoinGoTrade[.]com had a valid Sectigo SSL certificate (Obtain Capabilities: Digital Certificates [T1588.004]). The SSL certificate was “Domain Control Validated,” a weak security verification level that does not require validation of the owner’s identity or the actual business’s existence.

CoinGoTrade Application Analysis

Windows Program

The Windows version of the malicious application is an MSI Installer. The installer appears to be legitimate and will execute the following actions.

• Installs CoinGoTrade.exe in folder C:\Program Files (x86)\CoinGoTrade
• Installs CoinGoTradeUpdate.exe in folder C:\Users\<username>\AppData\Roaming\CoinGoTradeSupport
• Runs CoinGoTradeUpdate.exe

CoinGoTrade.exe loads a legitimate-looking cryptocurrency wallet platform with no signs of malicious activity and is a copy of an open-source cryptocurrency application.

CoinGoTradeUpdate.exe first installs itself as a service (Create or Modify System Process: Windows Service [T1543.003]), which will automatically start when any user logs on (Boot or Logon Autostart Execution [T1547]). The service is installed with a description stating it is an “Automatic CoinGoTrade Upgrade.” When launched, it collects the victim’s host information (System Owner/User Discovery [T1033]), combines the information in strings before exfiltration, and sends it to a C2 website (Exfiltration Over C2 Channel [T1041]).

macOS X Program

The macOS version of the malicious application is a DMG Installer. The installer looks legitimate and has very similar functionality to the Windows version, but it does not have a digital certificate and will warn the user of that before installation. The installer executes the following actions.

• Installs CoinGoTrade in folder /Applications/CoinGoTrade.app/Contents/MacOS/
• Installs CoinGoTradeUpgradeDaemon in folder /Applications/CoinGoTrade.app/Contents/MacOS/
• Executes a postinstall script
  • Creates CoinGoTradeService folder in /Library/Application Support folder
  • Moves CoinGoTradeUpgradeDaemon to the new folder
  • Moves com.coingotrade.pkg.product.plist to folder /Library/LaunchDaemons/
  • Runs CoinGoTradeUpgradeDaemon in the background

The CoinGoTrade program is likely a copy of an open-source cryptocurrency wallet application and loads a legitimate-looking, fully functional wallet program).

The CoinGoTradeUpgradeDaemon program calls its function CheckUpdate (which contains most of the logic functionality of the malware) and sends a POST to the C2 server with a connection named “CoinGoTrade 1.0 (Check Update Osx)” (Application Layer Protocol: Web Protocols [T1071.001]). If the C2 server returns a file, it is decoded and written to the victim’s folder /private/tmp/updatecoingotrade with permissions set by the command chmod 700 (only the user can read, write, and execute) (Command and Scripting Interpreter [T1059]). Stage 2 is then launched, and the malware, CoinGoTradeUpgradeDaemon, returns to sleeping and checking in with the C2 server at predetermined intervals (Application Layer Protocol: Web Protocols [T1071.001]).

The postinstall script has similar functionality to the other scripts (Command and Scripting Interpreter: AppleScript [T1059.002]) and installs CoinGoTrade and CoinGoTradeUpgradeDaemon in folder /Applications/CoinGoTrade.app/Contents/MacOS/. It moves the property list (plist) file com.coingotrade.pkg.product.plist to the /Library/LaunchDaemons/ folder (Scheduled Task/Job: Launchd [T1053.004]). Because the LaunchDaemon will not run automatically after the plist file is moved, the postinstall script launches CoinGoTradeUpgradeDaemon and runs it in the background (Create or Modify System Process: Launch Daemon [T1543.004]).

Payload

The Windows malware’s payload could not be downloaded because the C2 server is no longer accessible. Additionally, none of the open-source reporting for this sample contained copies of the payload. The Windows payload is likely similar in functionality to the macOS X stage 2 detailed below.

The stage 2 payload for the macOS X malware was no longer available from the specified download URL. Still, a file was submitted to VirusTotal by the same user on the same date as the macOS X CoinGoTradeUpgradeDaemon. These clues suggest that the submitted file may be related to the macOS X version of the malware and the downloaded payload.

The file prtspool is a 64-bit Mach-O executable with a large variety of features that have all been confirmed as functionality. The file has three C2 URLs hardcoded into the file and communicates to these with HTTP POST multipart-form data boundary string. Like other HIDDEN COBRA malware, prtspool uses format strings to store data collected about the system and sends it to the C2s.

For more details on AppleJeus Version 5: CoinGoTrade, see MAR-10322463-5.v1.

AppleJeus Version 6: Dorusio

Introduction and Infrastructure

In March 2020, an additional version of the AppleJeus malware was identified. This time the malware was marketed and distributed by a legitimate-looking company called Dorusio on their website, dorusio[.]com (Acquire Infrastructure: Domain [T1583.001]). Researchers collected samples for Windows and macOS X versions of the Dorusio Wallet (Develop Capabilities: Malware [T1587.001]). As of at least early 2020, the actual download links result in 404 errors. The download page has release notes with version revisions claiming to start with version 1.0.0, released on April 15, 2019.

The domain dorusio[.]com resolved to IP address 198.54.115[.]51 from March 30, 2020 to January 23, 2021. The IP address is controlled by NameCheap Inc. (ASN 22612) and is located in Atlanta, GA. This IP address is in the same ASN for CoinGoTrade[.]com and Ants2Whale[.]com.

The domain dorusio[.]com had a valid Sectigo SSL certificate (Obtain Capabilities: Digital Certificates [T1588.004]). The SSL certificate was “Domain Control Validated,” a weak security verification level that does not require validation of the owner’s identity or the actual business’s existence.

Dorusio Application Analysis

Windows Program

The Windows version of the malicious application is an MSI Installer. The installer appears to be legitimate and will install the following two programs.

• Installs Dorusio.exe in folder C:\Program Files (x86)\Dorusio
• Installs DorusioUpgrade.exe in folder C:\Users\<username>\AppData\Roaming\DorusioSupport
• Runs DorusioUpgrade.exe

The program, Dorusio.exe, loads a legitimate-looking cryptocurrency wallet platform with no signs of malicious activity and is a copy of an open-source cryptocurrency application.

The program DorusioUpgrade.exe first installs itself as a service (Create or Modify System Process: Windows Service [T1543.003]), which will automatically start when any user logs on (Boot or Logon Autostart Execution [T1547]). The service is installed with a description stating it “Automatic Dorusio Upgrade.” When launched, it collects the victim’s host information (System Owner/User Discovery [T1033]), combines the information in strings before exfiltration, and sends it to a C2 website (Exfiltration Over C2 Channel [T1041]).

macOS X Program

The macOS version of the malicious application is a DMG Installer. The installer looks legitimate and has very similar functionality to the Windows version, but it does not have a digital certificate and will warn the user of that before installation. The installer executes the following actions.

• Installs Dorusio in folder /Applications/Dorusio.app/Contents/MacOS/
• Installs Dorusio_upgrade in folder /Applications/Dorusio.app/Contents/MacOS/
• Executes a postinstall script
  • Creates DorusioDaemon folder in /Library/Application Support folder
  • Moves Dorusio_upgrade to the new folder
  • Moves com.dorusio.pkg.wallet.plist to folder /Library/LaunchDaemons/
  • Runs Dorusio_upgrade in the background

The Dorusio program is likely a copy of an open-source cryptocurrency wallet application and loads a legitimate-looking wallet program (fully functional). Aside from the Dorusio logo and two new services, the wallet appears to be the same as the Kupay Wallet. This application seems to be a modification of the open-source cryptocurrency wallet Copay distributed by Atlanta-based company BitPay.

The Dorusio_upgrade program calls its function CheckUpdate (which contains most of the logic functionality of the malware) and sends a POST to the C2 server with a connection named “Dorusio Wallet 2.1.0 (Check Update Osx)” (Application Layer Protocol: Web Protocols [T1071.001]). If the C2 server returns a file, it is decoded and written to the victim’s folder /private/tmp/Dorusio_update with permissions set by the command chmod 700 (only the user can read, write, and execute) (Command and Scripting Interpreter [T1059]). Stage 2 is then launched, and the malware, Dorusio_upgrade, returns to sleeping and checking in with the C2 server at predetermined intervals (Application Layer Protocol: Web Protocols [T1071.001]).

The postinstall script has similar functionality to other AppleJeus scripts (Command and Scripting Interpreter: AppleScript [T1059.002]). It creates the DorusioDaemon folder in /Library/Application Support folder and then moves Dorusio_upgrade to the new folder. It moves the property list (plist) file com.dorusio.pkg.wallet.plist from the Installer package to the /Library/LaunchDaemons/ folder (Scheduled Task/Job: Launchd [T1053.004]). Because the LaunchDaemon will not run automatically after the plist file is moved, the postinstall script launches Dorusio_upgrade and runs it in the background (Create or Modify System Process: Launch Daemon [T1543.004]).

Payload

Neither the payload for the Windows nor macOS X malware could be downloaded; the C2 server is no longer accessible. The payloads are likely similar in functionality to the macOS X stage 2 from CoinGoTrade and Kupay Wallet, or the Windows stage 2 from Union Crypto.

For more details on AppleJeus Version 6: Dorusio, see MAR-10322463-6.v1.

AppleJeus 4, 5, and 6 Installation Conflictions

If a user attempts to install the Kupay Wallet, CoinGoTrade, and Dorusio applications on the same system, they will encounter installation conflicts.

If Kupay Wallet is already installed on a system and the user tries to install CoinGoTrade or Dorusio:

• Pop-up windows appear, stating a more recent version of the program is already installed.

If CoinGoTrade is already installed on a system and the user attempts to install Kupay Wallet:

• Kupay.exe will be installed in the C:\Program Files (x86)\CoinGoTrade\ folder.
• All CoinGoTrade files will be deleted.
• The folders and files contained in the C:\Users\<username>\AppData\Roaming\CoinGoTradeSupport will remain installed.
• KupayUpgrade.exe is installed in the new folder C:\Users\<username>\AppData\Roaming\KupaySupport.

If Dorusio is already installed on a system and the user attempts to install Kupay Wallet:

• Kupay.exe will be installed in the C:\Program Files (x86)\Dorusio\ folder.
• All Dorusio.exe files will be deleted.
• The folders and files contained in C:\Users\<username>\AppData\Roaming\DorusioSupport will remain installed.
• KupayUpgrade.exe is installed in the new folder C:\Users\<username>\AppData\Roaming\KupaySupport.

AppleJeus Version 7: Ants2Whale

Introduction and Infrastructure

In late 2020, a new version of AppleJeus was identified called “Ants2Whale.” The site for this version of AppleJeus is ants2whale[.]com (Acquire Infrastructure: Domain [T1583.001]). The website shows a legitimate-looking cryptocurrency company and application. The website contains multiple spelling and grammar mistakes indicating the creator may not have English as a first language. The website states that to download Ants2Whale, a user must contact the administrator, as their product is a “premium package” (Develop Capabilities: Malware [T1587.001]).

The domain ants2whale[.]com resolved to IP address 198.54.114[.]237 from September 23, 2020, to January 22, 2021. The IP address is controlled by NameCheap, Inc. (ASN 22612) and is located in Atlanta, GA. This IP address is in the same ASN for CoinGoTrade[.]com and Dorusio[.]com.

The domain ants2whale[.]com had a valid Sectigo SSL certificate (Obtain Capabilities: Digital Certificates [T1588.004]). The SSL certificate was “Domain Control Validated,” a weak security verification level that does not require validation of the owner’s identity or the actual business’s existence.

Ants2Whale Application Analysis

Windows Program

As of late 2020, the Windows program was not available on VirusTotal. It is likely very similar to the macOS X version detailed below.

macOS X Program

The macOS version of the malicious application is a DMG Installer. The installer looks legitimate and has very similar functionality to the Windows version, but it does not have a digital certificate and will warn the user of that before installation. The installer executes the following actions.

• Installs Ants2Whale in folder /Applications/Ants2whale.app/Contents/MacOS/Ants2whale
• Installs Ants2WhaleHelper in folder /Library/Application Support/Ants2WhaleSupport/
• Executes a postinstall script
  • Moves com.Ants2whale.pkg.wallet.plist to folder /Library/LaunchDaemons/
  • Runs Ants2WhaleHelper in the background

The Ants2Whale and Ants2WhaleHelper programs and the postinstall script function almost identically to previous versions of AppleJeus and will not be discussed in depth in this advisory.

For more details on AppleJeus Version 7: Ants2Whale, see MAR-10322463-7.v1.

ATT&CK Profile

Figure 2 and table 2 provide summaries of the MITRE ATT&CK techniques observed.

Figure 2: MITRE ATT&CK enterprise techniques used by AppleJeus

Table 2: MITRE ATT&CK techniques observed

Mitigations

Compromise Mitigations

Organizations that identify AppleJeus malware within their networks should take immediate action. Initial actions should include the following steps.

• Contact the FBI, CISA, or Treasury immediately regarding any identified activity related to AppleJeus. (Refer to the Contact Information section below.)
• Initiate your organization’s incident response plan.
• Generate new keys for wallets, and/or move to new wallets.
• Introduce a two-factor authentication solution as an extra layer of verification.  
• Use hardware wallets, which keep the private keys in a separate, secured storage area.
• To move funds out off a compromised wallet:
  • Do not use the malware listed in this advisory to transfer funds, and  
  • Form all transactions offline and then broadcast them to the network all at once in a short online session, ideally prior to the attacker accessing them.
• Remove impacted hosts from network.
• Assume the threat actors have moved laterally within the network and downloaded additional malware.
• Change all passwords to any accounts associated with impacted hosts.
• Reimage impacted host(s).  
• Install anti-virus software to run daily deep scans of the host.
• Ensure your anti-virus software is setup to download the latest signatures daily.
• Install a Host Based Intrusion Detection (HIDS)-based software and keep it up to date.
• Ensure all software and hardware is up to date, and all patches have been installed.
• Ensure network-based firewall is installed and/or up to date.
• Ensure the firewall’s firmware is up to date.

Pro-Active Mitigations

Consider the following recommendations for defense against AppleJeus malware and related activity.

Cryptocurrency Users

• Verify source of cryptocurrency-related applications.
• Use multiple wallets for key storage, striking the appropriate risk balance between hot and cold storage.
• Use custodial accounts with multi-factor authentication mechanisms for both user and device verification.
• Patronize cryptocurrency service businesses that offer indemnity protections for lost or stolen cryptocurrency.
• Consider having a dedicated device for cryptocurrency management.

Financial Service Companies

• Verify compliance with Federal Financial Institutions Examination Council (FFIEC) handbooks at https://ithandbook.ffiec.gov, especially those related to information security.
• Report suspicious cyber and financial activities. For more information on mandatory and voluntary reporting of cyber events via suspicious activity reports, see the Financial Crimes Enforcement Network (FinCEN) Advisory FIN-2016-A005: Advisory to Financial Institutions on Cyber- Events and Cyber-Enabled Crime at https://www.fincen.gov/sites/default/files/advisory/2016-10-25/Cyber%20Threats%20Advisory%20-%20FINAL%20508_2.pdf and FinCEN’s Section 314(b) Fact Sheet at https://www.fincen.gov/sites/default/files/shared/314bfactsheet.pdf.

Cryptocurrency Businesses

• Verify compliance with the Cryptocurrency Security Standard at http://cryptoconsortium.github.io/CCSS/.

All Organizations

• Incorporate IOCs identified in CISA’s Malware Analysis Reports on https://us-cert.cisa.gov/northkorea into intrusion detection systems and security alert systems to enable active blocking or reporting of suspected malicious activity.
• See table 3 below, which provides a summary of preventative ATT&CK mitigations based on observed techniques.

Table 3: MITRE ATT&CK mitigations based on observed techniques

Contact Information

Recipients of this report are encouraged to contribute any additional information that they may have related to this threat.

For any questions related to this report or to report an intrusion and request resources for incident response or technical assistance, please contact:

• The FBI through the FBI Cyber Division (855-292-3937 or CyWatch@fbi.gov) or a local field office,
• CISA (888-282-0870 or Central@cisa.dhs.gov), or
• Treasury Office of Cybersecurity and Critical Infrastructure Protection (Treasury OCCIP) (202-622-3000 or OCCIP-Coord@treasury.gov).

References

• [1] CISA Alert AA20-239A: FASTCash 2.0: North Korea's BeagleBoyz Robbing Banks
• [2] Department of the Treasury Press Release: Treasury Sanctions Individuals Laundering Cryptocurrency for Lazarus Group
• [3] Department of Justice Press Release: Two Chinese Nationals Charged with Laundering Over $100 Million in Cryptocurrency From Exchange Hack
• [4] CISA Alert TA17-318A: HIDDEN COBRA – North Korean Remote Administration Tool: FALLCHILL
• [5] CISA Alert TA17-318A: HIDDEN COBRA – North Korean Remote Administration Tool: FALLCHILL
• [6] MITRE ATT&CK Software: FALLCHILL
• [7] SecureList: Operation AppleJeus Sequel
• [8] GitHub: Blackbird Bitcoin Arbitrage

Revisions

• February 17, 2021: Initial Version

AA21-042A: Compromise of U.S. Water Treatment Facility
Original release date: February 11, 2021 | Last revised: February 12, 2021

Summary

On February 5, 2021, unidentified cyber actors obtained unauthorized access to the supervisory control and data acquisition (SCADA) system at a U.S. drinking water treatment facility. The unidentified actors used the SCADA system’s software to increase the amount of sodium hydroxide, also known as lye, a caustic chemical, as part of the water treatment process. Water treatment plant personnel immediately noticed the change in dosing amounts and corrected the issue before the SCADA system’s software detected the manipulation and alarmed due to the unauthorized change. As a result, the water treatment process remained unaffected and continued to operate as normal. The cyber actors likely accessed the system by exploiting cybersecurity weaknesses, including poor password security, and an outdated operating system. Early information indicates it is possible that a desktop sharing software, such as TeamViewer, may have been used to gain unauthorized access to the system, although this cannot be confirmed at present date. Onsite response to the incident included Pinellas County Sheriff Office (PCSO), U.S. Secret Service (USSS), and the Federal Bureau of Investigation (FBI).

The FBI, the Cybersecurity and Infrastructure Security Agency (CISA), the Environmental Protection Agency (EPA), and the Multi-State Information Sharing and Analysis Center (MS-ISAC) have observed cyber criminals targeting and exploiting desktop sharing software and computer networks running operating systems with end of life status to gain unauthorized access to systems. Desktop sharing software, which has multiple legitimate uses—such as enabling telework, remote technical support, and file transfers—can also be exploited through malicious actors’ use of social engineering tactics and other illicit measures. Windows 7 will become more susceptible to exploitation due to lack of security updates and the discovery of new vulnerabilities. Microsoft and other industry professionals strongly recommend upgrading computer systems to an actively supported operating system. Continuing to use any operating system within an enterprise beyond the end of life status may provide cyber criminals access into computer systems.

Click here for a PDF version of this report.

Technical Details

Desktop Sharing Software

The FBI, CISA, EPA, and MS-ISAC have observed corrupt insiders and outside cyber actors using desktop sharing software to victimize targets in a range of organizations, including those in the critical infrastructure sectors. In addition to adjusting system operations, cyber actors also use the following techniques:

• Use access granted by desktop sharing software to perform fraudulent wire transfers.
• Inject malicious code that allows the cyber actors to
  • Hide desktop sharing software windows,
  • Protect malicious files from being detected, and
  • Control desktop sharing software startup parameters to obfuscate their activity.
• Move laterally across a network to increase the scope of activity.

TeamViewer, a desktop sharing software, is a legitimate popular tool that has been exploited by cyber actors engaged in targeted social engineering attacks, as well as large scale, indiscriminate phishing campaigns. Desktop sharing software can also be used by employees with vindictive and/or larcenous motivations against employers.

Beyond its legitimate uses, when proper security measures aren’t followed, remote access tools may be used to exercise remote control over computer systems and drop files onto victim computers, making it functionally similar to Remote Access Trojans (RATs). TeamViewer’s legitimate use, however, makes anomalous activity less suspicious to end users and system administrators compared to RATs.

Windows 7 End of Life

On January 14, 2020, Microsoft ended support for the Windows 7 operating system, which includes security updates and technical support unless certain customers purchased an Extended Security Update (ESU) plan. The ESU plan is paid per-device and available for Windows 7 Professional and Enterprise versions, with an increasing price the longer a customer continues use. Microsoft will only offer the ESU plan until January 2023. Continued use of Windows 7 increases the risk of cyber actor exploitation of a computer system.

Cyber actors continue to find entry points into legacy Windows operating systems and leverage Remote Desktop Protocol (RDP) exploits. Microsoft released an emergency patch for its older operating systems, including Windows 7, after an information security researcher discovered an RDP vulnerability in May 2019. Since the end of July 2019, malicious RDP activity has increased with the development of a working commercial exploit for the vulnerability. Cyber actors often use misconfigured or improperly secured RDP access controls to conduct cyberattacks. The xDedic Marketplace, taken down by law enforcement in 2019, flourished by compromising RDP vulnerabilities around the world.

Mitigations

General Recommendations

The following cyber hygiene measures may help protect against the aforementioned scheme:

• Update to the latest version of the operating system (e.g., Windows 10).
• Use multiple-factor authentication.
• Use strong passwords to protect Remote Desktop Protocol (RDP) credentials.
• Ensure anti-virus, spam filters, and firewalls are up to date, properly configured, and secure.
• Audit network configurations and isolate computer systems that cannot be updated.
• Audit your network for systems using RDP, closing unused RDP ports, applying multiple-factor authentication wherever possible, and logging RDP login attempts.
• Audit logs for all remote connection protocols.
• Train users to identify and report attempts at social engineering.
• Identify and suspend access of users exhibiting unusual activity.

Water and Wastewater Systems Security Recommendations

The following physical security measures serve as additional protective measures:

• Install independent cyber-physical safety systems. These are systems that physically prevent dangerous conditions from occurring if the control system is compromised by a threat actor.
• Examples of cyber-physical safety system controls include:
  • Size of the chemical pump
  • Size of the chemical reservoir
  • Gearing on valves
  • Pressure switches, etc.

The benefit of these types of controls in the water sector is that smaller systems, with limited cybersecurity capability, can assess their system from a worst-case scenario. The operators can take physical steps to limit the damage. If, for example, cyber actors gain control of a sodium hydroxide pump, they will be unable to raise the pH to dangerous levels.

Remote Control Software Recommendations

For a more secured implementation of TeamViewer software:

• Do not use unattended access features, such as “Start TeamViewer with Windows” and “Grant easy access.”
• Configure TeamViewer service to “manual start,” so that the application and associated background services are stopped when not in use.
• Set random passwords to generate 10-character alphanumeric passwords.
• If using personal passwords, utilize complex rotating passwords of varying lengths. Note: TeamViewer allows users to change connection passwords for each new session. If an end user chooses this option, never save connection passwords as an option as they can be leveraged for persistence.
• When configuring access control for a host, utilize custom settings to tier the access a remote party may attempt to acquire.
• Require remote party to receive confirmation from the host to gain any access other than “view only.” Doing so will ensure that, if an unauthorized party is able to connect via TeamViewer, they will only see a locked screen and will not have keyboard control.
• Utilize the ‘Block and Allow’ list which enables a user to control which other organizational users of TeamViewer may request access to the system. This list can also be used to block users suspected of unauthorized access.

Contact Information

To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at www.fbi.gov/contact-us/field, or the FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by e-mail at CyWatch@fbi.gov or your local WMD Coordinator. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact.

To request incident response resources or technical assistance related to these threats, contact CISA at Central@cisa.dhs.gov.

Revisions

• February 11, 2021: Initial Version
• February 12, 2021: Update to PDF File

AA21-008A: Detecting Post-Compromise Threat Activity in Microsoft Cloud Environments
Original release date: January 8, 2021 | Last revised: February 4, 2021

Summary

This Advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework. See the ATT&CK for Enterprise for all referenced threat actor tactics and techniques.

This Alert is a companion alert to AA20-352A: Advanced Persistent Threat Compromise of Government Agencies, Critical Infrastructure, and Private Sector Organizations. AA20-352A primarily focuses on an advanced persistent threat (APT) actor’s compromise of SolarWinds Orion products as an initial access vector into networks of U.S. Government agencies, critical infrastructure entities, and private network organizations. As noted in AA20-352A, the Cybersecurity and Infrastructure Security Agency (CISA) has evidence of initial access vectors in addition to the compromised SolarWinds Orion products.

This Alert also addresses activity—irrespective of the initial access vector leveraged—that CISA attributes to an APT actor. Specifically, CISA has seen an APT actor using compromised applications in a victim’s Microsoft 365 (M365)/Azure environment. CISA has also seen this APT actor utilizing additional credentials and Application Programming Interface (API) access to cloud resources of private and public sector organizations. These tactics, techniques, and procedures (TTPs) feature three key components:

• Compromising or bypassing federated identity solutions;
• Using forged authentication tokens to move laterally to Microsoft cloud environments; and
• Using privileged access to a victim’s cloud environment to establish difficult-to-detect persistence mechanisms for Application Programming Interface (API)-based access.

This Alert describes these TTPs and offers an overview of, and guidance on, available open-source tools—including a CISA-developed tool, Sparrow—for network defenders to analyze their Microsoft Azure Active Directory (AD), Office 365 (O365), and M365 environments to detect potentially malicious activity.

Note: this Alert describes artifacts—presented by these attacks—from which CISA has identified detectable evidence of the threat actor’s initial objectives. CISA continues to analyze the threat actor’s follow-on objectives.

Technical Details

Frequently, CISA has observed the APT actor gaining Initial Access [TA0001] to victims’ enterprise networks via compromised SolarWinds Orion products (e.g., Solorigate, Sunburst).[1] However, CISA is investigating instances in which the threat actor may have obtained initial access by Password Guessing [T1110.001], Password Spraying [T1110.003], and/or exploiting inappropriately secured administrative or service credentials (Unsecured Credentials [T1552]) instead of utilizing the compromised SolarWinds Orion products.

CISA observed this threat actor moving from user context to administrator rights for Privilege Escalation [TA0004] within a compromised network and using native Windows tools and techniques, such as Windows Management Instrumentation (WMI), to enumerate the Microsoft Active Directory Federated Services (ADFS) certificate-signing capability. This enumeration allows threat actors to forge authentication tokens (OAuth) to issue claims to service providers—without having those claims checked against the identity provider—and then to move laterally to Microsoft Cloud environments (Lateral Movement [TA0008]).

The threat actor has also used on-premises access to manipulate and bypass identity controls and multi-factor authentication. This activity demonstrates how sophisticated adversaries can use credentials from one portion of an organization to move laterally (Lateral Movement [TA0008]) through trust boundaries, evade defenses and detection (Defense Evasion [TA0005]), and steal sensitive data (Collection [TA0009]).

This level of compromise is challenging to remediate and requires a rigorous multi-disciplinary effort to regain administrative control before recovering.

Mitigations

Detection

Guidance on identifying affected SolarWinds software is well documented.[2] However—once an organization identifies a compromise via SolarWinds Orion products or other threat actor TTPs—identifying follow-on activity for on-premises networks requires fine-tuned network and host-based forensics.

The nature of cloud forensics is unique due to the growing and rapidly evolving technology footprints of major vendors. Microsoft's O365 and M365 environments have built-in capabilities for detecting unusual activity. Microsoft also provides premium services (Advanced Threat Protection [ATP] and Azure Sentinel), which enable network defenders to investigate TTPs specific to the Solorigate activity.[3]

Detection Tools

CISA is providing examples of detection tools for informational purposes only. CISA does not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services does not constitute or imply their endorsement, recommendation, or favoring by CISA.

There are a number of open-source tools available to investigate adversary activity in Microsoft cloud environments and to detect unusual activity, service principals, and application activity.[4] Publicly available PowerShell tools that network defenders can use to investigate M365 and Microsoft Azure include:

• CISA's Sparrow,
• Open-source utility Hawk, and
• CrowdStrike's Azure Reporting Tool (CRT).

Additionally, Microsoft's Office 365 Management API and Graph API provide an open interface for ingesting telemetry and evaluating service configurations for signs of anomalous activity and intrusion.

Note: these open-source tools are highlighted and explained to assist with on-site investigation and remediation in cloud environments but are not all-encompassing. Open source tools can be complemented by services such as Azure Sentinel, a Microsoft premium service that provides comprehensive analysis tools, including custom detections for the activity indicated.

General Guidance on Using Detection Tools

1. Audit the creation and use of service principal credentials. Look for unusual application usage, such as use of dormant applications.
2. Audit the assignment of credentials to applications that allow non-interactive sign-in by the application. Look for unexpected trust relationships added to the Azure Active Directory.
3. Download the interactive sign-ins from the Azure admin portal or use the Microsoft Sentinel product. Review new token validation time periods with high values and investigate whether it was a legitimate change or an attempt to gain persistence by a threat actor.

Sparrow

CISA created Sparrow to help network defenders detect possible compromised accounts and applications in the Azure/M365 environment. The tool focuses on the narrow scope of user and application activity endemic to identity- and authentication-based attacks seen recently in multiple sectors. It is neither comprehensive nor exhaustive of available data. It is intended to narrow a larger set of available investigation modules and telemetry to those specific to recent attacks on federated identity sources and applications.

CISA advises Sparrow users to take the following actions.

1. Use Sparrow to detect any recent domain authentication or federation modifications.
   1. Domain and federation modification operations are uncommon and should be investigated.
2. Examine logs for new and modified credentials applied to applications and service principals; delineate for the credential type. Sparrow can be used to detect the modification of service principals and application credentials.
   1. Create a timeline for all credential changes, focusing on recent wholesale changes.
   2. Review the “top actors” for activity in the environment and the number of credential modifications performed.
   3. Monitor changes in application and service principal credentials.
   4. Investigate any instances of excessive permissions being granted, including, but not limited to, Exchange Online, Microsoft Graph, and Azure AD Graph.
3. Use Sparrow to detect privilege escalation, such as adding a service principal, user, or group to a privileged role.
4. Use Sparrow to detect OAuth consent and users’ consent to applications, which is useful for interpreting changes in adversary TTPs.
5. Use Sparrow to identify anomalous Security Assertion Markup Language (SAML) token sign-ins by pivoting on the unified audit log UserAuthenticationValue of 16457, which is an indicator of how a SAML token was built and is a potential indicator for forged SAML tokens.
   1. Note that this TTP has not been the subject of significant published security research but may indicate an unusual usage of a token, such as guest access for external partners to M365 resources.
6. Review the PowerShell logs that Sparrow exports.
   1. Review PowerShell mailbox sign-ins and validate that the logins are legitimate actions.
   2. Review PowerShell usage for users with PowerShell in the environment.
7. Use Sparrow to check the Graph API application permissions of all service principals and applications in M365/Azure AD.
   1. Investigate unusual activity regarding Microsoft Graph API permissions (using either the legacy https://graph.windows.net/ or https://graph.microsoft.com). Graph is used frequently as part of these TTPs, often to access and manipulate mailbox resources.
8. Review Sparrow’s listed tenant’s Azure AD domains, to see if the domains have been modified.
9. For customers with G5 or E5 licensing levels, review MailItemsAccessed for insight into what application identification (ID) was used for accessing users’ mailboxes. Use Sparrow to query for a specific application ID using the app id investigation capability, which will check to see if it is accessing mail or file items.
   1. The MailItemsAccessed event provides audibility for mailbox data accessed via mail protocols or clients.
   2. By analyzing the MailItemsAccessed action, incident responders can determine which user mailbox items have been accessed and potentially exfiltrated by a threat actor. This event will be recorded even in some situations where the message was not necessarily read interactively (e.g., bind or sync).[5]
   3. The resulting suspicious application ID can provide incident responders with a pivot to detect other suspicious applications that require additional analysis.
   4. Check for changes to applications with regards to the accessing of resources such as mail or file items.

Hawk

Hawk is an open-source, PowerShell-driven, community-developed tool network defenders can use to quickly and easily gather data from O365 and Azure for security investigations. Incident responders and network defenders can investigate specific user principals or the entire tenant. Data it provides include IP addresses and sign-in data. Additionally, Hawk can track IP usage for concurrent login situations.

Hawk users should review login details for administrator accounts and take the following steps.

1.  Investigate high-value administrative accounts to detect anomalous or unusual activity (Global Admins).
2. Enable PowerShell logging, and evaluate PowerShell activity in the environment not used for traditional or expected purposes.
   1. PowerShell logging does not reveal the exact cmdlet that was run on the tenant.
3. Look for users with unusual sign-in locations, dates, and times.
4. Check permissions of service principals and applications in M365/Azure AD.
5. Detect the frequency of resource access from unusual places. Use the tool to pivot to a trusted application and see if it is accessing mail or file items.
6. Review mailbox rules and recent mailbox rule changes.

CrowdStrike Azure Reporting Tool

CrowdStrike's Azure Reporting Tool (CRT) can help network defenders analyze their Microsoft Azure AD and M365 environment to help organizations analyze permissions in their Azure AD tenant and service configuration. This tool has minor overlap with Sparrow; it shows unique items, but it does not cover the same areas. CISA is highlighting this tool because it is one of the only free, open-source tools available to investigate this activity and could be used to complement Sparrow.

Detection Tool Distinctions

• Sparrow differs from CRT by looking for specific indicators of compromise associated with the recent attacks.
• CRT focuses on the tenant’s Azure AD permissions and Exchange Online configuration settings instead of the unified audit log, which gives it a different output from Sparrow or Hawk.
• CRT returns the same broad scope of application/delegated permissions for service principals and applications as Hawk.
• As part of its investigation, Sparrow homes in on a narrow set of application permissions given to the Graph API, which is common to the recent attacks.
• CRT looks at Exchange Online federation configuration and federation trust, while Sparrow focuses on listing Azure AD domains.
• Among the items network defenders can use CRT to review are delegated permissions and application permissions, federation configurations, federation trusts, mail forwarding rules, service principals, and objects with KeyCredentials.

Detection Methods

Microsoft breaks the threat actor’s recent activity into four primary stages, which are described below along with associated detection methods. Microsoft describes these stages as beginning with all activity after the compromise of the on-premises identity solution, such as ADFS.[6]

Note: this step provides an entry vector to cloud technology environments, and is unnecessary when the threat actor has compromised an identity solution or credential that allows the APT direct access to the cloud(e.g., without leveraging the SolarWinds Orion vulnerability).

Stage 1: Forging a trusted authentication token used to access resources that trust the on-premises identity provider

These attacks (often referred to as “Golden Security Assertion Markup Language” attacks) can be analyzed using a combination of cloud-based and standard on-premises techniques.[7] For example, network defenders can use OAuth claims for specific principals made at the Azure AD level and compare them to the on-premises identity.

Export sign-in logs from the Azure AD portal and look at the Authentication Method field.

Note: at portal.azure.com, click on a user and review the authentication details (e.g., date, method, result). Without Sentinel, this is the only way to get these logs, which are critical for this effort.

Detection Method 1: Correlating service provider login events with corresponding authentication events in Active Directory Federation Services (ADFS) and Domain Controllers

Using SAML single sign-on, search for any logins to service providers that do not have corresponding event IDs 4769, 1200, and 1202 in the domain.

Detection Method 2: Identifying certificate export events in ADFS

Look for:

1. The IP address and Activity_ID in EventCode 410 and the Activity_ID and Instance_ID in EventCode 500.
2. Export-PfxCertificate or certutil-exportPFX in Event IDs 4103 and 4104, which may include detection of a certificate extraction technique.
3. Deleted certificate extraction with ADFSdump performed using Sysmon Event ID 18 with the pipe name \microsoft##wid\tsql\query (exclude processes regularly making this pipe connection on the machine).
4. Event ID 307 (The Federation Service configuration was changed), which can be correlated to relevant Event ID 510 with the same instance ID for change details (Event ID 510 with the same Instance ID could be more than one event per single Event ID 307 event).

Detection Method 3: Customizing SAML response to identify irregular access

This method serves as prevention for the future (and would only detect future, not past, activity), as it helps identify irregularities from the point of the change forward. Organizations can modify SAML responses to include custom elements for each service provider to monitor and detect any anomalous requests.[8]

Detection Method 4: Detecting malicious ADFS trust modification

A threat actor who gains administrative access to ADFS can add a new, trusted ADFS rather than extracting the certificate and private key as part of a standard Golden SAML attack.[9]
Network defenders should look for:

1. Event ID 307 (The Federation Service configuration was changed), which can be correlated to relevant Event ID 510 with the same Instance ID for change details. (Event ID 510 with the same Instance ID could be more than one event per single Event ID 307 event.)
   1. Review events, particularly searching for Configuration: Type: IssuanceAuthority where Property Value references an unfamiliar domain.
2. Possible activity of an interrogating ADFS host by using ADFS PowerShell plugins. Look for changes in the federation trust environment that would indicate new ADFS sources.

Stage 2: Using the forged authentication token to create configuration changes in the Service Provider, such as Azure AD (establishing a foothold)

After the threat actor has compromised the on-premises identity provider, they identify their next series of objectives by reviewing activity in the Microsoft Cloud activity space (Microsoft Azure and M365 tenants).

The threat actor uses the ability to forge authentication tokens to establish a presence in the cloud environment. The actor adds additional credentials to an existing service principal. Once the threat actor has impersonated a privileged Azure AD account, they are likely to further manipulate the Azure/M365 environment (action on objectives in the cloud).

Network defenders should take the following steps.

1. Audit the creation and use of service principal and application credentials. Sparrow will detect modifications to these credentials.
   1. Look for unusual application usage, such as dormant or forgotten applications being used again.
   2. Audit the assignment of credentials to applications that allow non-interactive sign-in by the application.
2. Look for unexpected trust relationships that have been added to Azure AD. (Download the last 30 days of non-interactive sign-ins from the Azure portal or use Azure Sentinel.).[10]
3. Use Hawk (and any sub-modules available) to run an investigation on a specific user. Hawk will provide IP addresses, sign-in data, and other data. Hawk can also track IP usage in concurrent login situations.
4. Review login details for administrator accounts (e.g., high-value administrative accounts, such as Global Admins). Look for unusual sign-in locations, dates, and times.
5. Review new token validation time periods with high values and investigate whether the changes are legitimate or a threat actor’s attempts to gain persistence.

Stage 3: Acquiring an OAuth access token for the application using the forged credentials added to an existing application or service principal and calling APIs with the permissions assigned to that application

In some cases, the threat actor has been observed adding permissions to existing applications or service principals. Additionally the actor has been seen establishing new applications or service principals briefly and using them to add permissions to the existing applications or service principals, possibly to add a layer of indirection (e.g., using it to add a credential to another service principal, and then deleting it).[11]

Network defenders should use Sparrow to:

1. Examine highly privileged accounts; specifically using sign-in logs, look for unusual sign-in locations, dates, and times.
2. Create a timeline for all credential changes.
3. Monitor changes in application credentials (the script will export into csv named AppUpdate_Operations_Export).
4. Detect service principal credentials change and service principal change (e.g., if an actor adds new permissions or expands existing permissions).
   1. Export and view this activity via the ServicePrincipal_Operations_Export.
5. Record OAuth consent and consent to applications
   1. Export and view this record via the Consent_Operations_Export file.
6. Investigate instances of excessive high permissions, including, but not limited to Exchange Online, Microsoft Graph, and Azure AD Graph.
   1. Review Microsoft Graph API permissions granted to service principals.
   2. Export and view this activity via the ApplicationGraphPermissions csv file.
      1. Note: Hawk can also return the full list of service principal permissions for further investigation.
   3. Review top actors and the amount of credential modifications performed.
   4. Monitor changes in application credentials.
7. Identify manipulation of custom or third-party applications.
   1. Network defenders should review the catalog of custom or third-party vendors with applications in the Microsoft tenant and perform the above interrogation principles on those applications and trusts.
8. Review modifications to federation trust settings.
   1. Review new token validation time periods with high values and investigate whether this was a legitimate change or an attempt to gain persistence by the threat actor.
      1. The script detects the escalation of privileges, including the addition of Service Principals (SP) to privileged roles. Export this data into csv called AppRoleAssignment_Operations_Export.

Stage 4: Once access has been established, the threat actor Uses Microsoft Graph API to conduct action on objectives from an external RESTful API (queries impersonating existing applications).

Network defenders should:

1. In MailItemsAccessed operations, found within the Unified Audit Log (UAL), review the application ID used (requires G5 or E5 license for this specific detail).
2. Query the specific application ID, using the Sparrow script’s app ID investigation capability to interrogate mail and file items accessed for that applicationID (Use the application ID utility for any other suspicious apps that require additional analysis.).
3. Check the permissions of an application in M365/Azure AD using Sparrow.
   1. Hawk will return Azure_Application_Audit, and Sparrow will return ApplicationGraphPermissions.
   2. Network defenders will see the IP address that Graph API uses.
   3. Note: the Microsoft IP address may not show up as a virtual private server/anonymized endpoint.
4. Investigate a specific service principal, if it is a user-specific user account, in Hawk. This activity is challenging to see without Azure Sentinel or manually downloading and reviewing logs from the sign-in portal.

Microsoft Telemetry Nuances

The existing tools and techniques used to evaluate cloud-based telemetry sources present challenges not represented in traditional forensic techniques. Primarily, the amount of telemetry retention is far less than the traditional logging facilities of on-premises data sources. Threat actor activity that is more than 90 days old is unlikely to have been saved by traditional sources or be visible with the Microsoft M365 Management API or in the UAL.

Service principal logging is available using the Azure Portal via the "Service Principal Sign-ins" feature. Enable settings in the Azure Portal (see “Diagnostic Setting”) to ingest logs into Sentinel or a third-party security information and event management (SIEM) tool. An Azure Premium P1 or Premium P2 license is necessary to access this setting as well as other features, such as a log analytics workspace, storage account, or event hub.[12] These logs must be downloaded manually if not ingested by one of the methods listed in the Detection Methods section.

Global Administrator rights are often required by tools other than Hawk and Sparrow to evaluate M365 cloud security posture. Logging capability and visibility of data varies by licensing models and subscription to premium services, such as Microsoft Defender for O365 and Azure Sentinel. According to CrowdStrike, "There was an inability to audit via API, and there is the requirement for global admin rights to view important information which we found to be excessive. Key information should be easily accessible."[13]

Documentation for specific event codes, such as UserAuthenticationMethod 16457, which may indicate a suspicious SAML token forgery, is no longer available in the M365 Unified Access Log. Auditing narratives on some events no longer exist as part of core Microsoft documentation sources.

The use of industry-standard SIEMs for log detection is crucial for providing historical context for threat hunting in Microsoft cloud environments. Standard G3/E3 licenses only provide 90 days of auditing; with the advanced auditing license that is provided with a G5/E5 license, audit logs can be extended to retain information for a year. CISA notes that this license change is proactive, rather than reactive: it allows enhanced visibility and features for telemetry from the moment of integration but does not provide retroactive visibility on previous events or historical context.

A properly configured SIEM can provide:

1. Longer term storage of log data.
2. Cross correlation of log data with endpoint data and network data (such as those produced by ADFS servers), endpoint detection and response data, and identity provider information.
3. Ability to query use of application connectors in Azure.

Built-in tools, such as Microsoft Cloud Services and M365 applications, provide much of the same visibility available from custom tools and are mapped to the MITRE ATT&CK framework and easy-to-understand dashboards.[14] However, these tools often do not have the ability to pull historical data older than seven days. Therefore, storage solutions that appropriately meet governance standards and usability metrics for analysts for the SIEM must be carefully planned and arranged.

Contact Information

CISA encourages recipients of this report to contribute any additional information that they may have related to this threat. For any questions related to this report, please contact CISA at

• 1-888-282-0870 (From outside the United States: +1-703-235-8832)
• central@cisa.dhs.gov (UNCLASS)
• us-cert@dhs.sgov.gov (SIPRNET)
• us-cert@dhs.ic.gov (JWICS)

CISA encourages you to report any suspicious activity, including cybersecurity incidents, possible malicious code, software vulnerabilities, and phishing-related scams. Reporting forms can be found on the CISA/US-CERT homepage at http://www.us-cert.cisa.gov/.

Resources

Azure Active Directory Workbook to Assess Solorigate Risk: https://techcommunity.microsoft.com/t5/azure-active-directory-identity/azure-ad-workbook-to-help-you-assess-solorigate-risk/ba-p/2010718

Volexity - Dark Halo Leverages SolarWinds Compromise to Breach Organizations: https://www.volexity.com/blog/2020/12/14/dark-halo-leverages-solarwinds-compromise-to-breach-organizations/

How to Find Activity with Sentinel: https://www.verboon.info/2020/10/monitoring-service-principal-sign-ins-with-azuread-and-azure-sentinel/

Third-Party Walkthrough of the Attack: https://dirkjanm.io/azure-ad-privilege-escalation-application-admin/

National Security Agency Advisory on Detecting Abuse of Authentication Mechanisms: https://media.defense.gov/2020/Dec/17/2002554125/-1/-1/0/AUTHENTICATION_MECHANISMS_CSA_U_OO_198854_20.PDF

Microsoft 365 App for Splunk: https://splunkbase.splunk.com/app/3786/

CISA Remediation Guidance: https://us-cert.cisa.gov/ncas/alerts/aa20-352a

References

• [1] ZDNet: A Second Hacking Group has Targeted SolarWinds Systems
• [2] CISA: Supply Chain Compromise
• [3] Microsoft SolarWinds Post-Compromise Hunting with Azure Sentinel
• [4] Microsoft Solorigate Resource Center
• [5] Advanced Audit in Microsoft 365
• [6] Microsoft: Understanding “Solorigate’s” Identity IOCs
• [7] Detection and Hunting of Golden SAML Attack:
• [8] Ibid
• [9] Ibid
• [10] Microsoft: AADServicePrincipalSignInLogs
• [11] Microsoft: Understanding “Solorigate’s” Identity IOCs
• [12] Azure Active Directory Sign-in Activity Reports
• [13] CrowdStrike: CrowdStrike Launches Free Tool to Identify and Help Mitigate Risks in Azure Active Directory
• [14] Microsoft 365 App for Splunk

Revisions

• Initial version: January 8, 2021
• February 4, 2021: Removed link and section for outdated product feedback form

AA20-352A: Advanced Persistent Threat Compromise of Government Agencies, Critical Infrastructure, and Private Sector Organizations
Original release date: December 17, 2020 | Last revised: February 8, 2021

Summary

The Cybersecurity and Infrastructure Security Agency (CISA) is aware of compromises of U.S. government agencies, critical infrastructure entities, and private sector organizations by an advanced persistent threat (APT) actor beginning in at least March 2020. This APT actor has demonstrated patience, operational security, and complex tradecraft in these intrusions. CISA expects that removing this threat actor from compromised environments will be highly complex and challenging for organizations.

(Updated January 6, 2021): One of the initial access vectors for this activity is a supply chain compromise of a Dynamic Link Library (DLL) in the following SolarWinds Orion products (see Appendix A). Note: prior versions of this Alert included a single bullet that listed two platform versions for the same DLL. For clarity, the Alert now lists these platform versions that share the same DLL version number separately, as both are considered affected versions.

• Orion Platform 2019.4 HF5, version 2019.4.5200.9083
• Orion Platform 2020.2 RC1, version 2020.2.100.12219
• Orion Platform 2020.2 RC2, version 2020.2.5200.12394
• Orion Platform 2020.2, version 2020.2.5300.12432
• Orion Platform 2020.2 HF1, version 2020.2.5300.12432

Note (updated January 6, 2021): CISA has evidence that there are initial access vectors other than the SolarWinds Orion platform and has identified legitimate account abuse as one of these vectors (for details refer to Initial Access Vectors section). Specifically, we are investigating incidents in which activity indicating abuse of Security Assertion Markup Language (SAML) tokens consistent with this adversary’s behavior is present, yet where impacted SolarWinds instances have not been identified. CISA is continuing to work to confirm initial access vectors and identify any changes to the tactics, techniques, and procedures (TTPs). CISA will update this Alert as new information becomes available. Refer to CISA.gov/supply-chain-compromise for additional resources.

(Updated January 6, 2021): On December 13, 2020, CISA released Emergency Directive 21-01: Mitigate SolarWinds Orion Code Compromise, ordering federal civilian executive branch departments and agencies to disconnect affected devices. CISA has subsequently issued supplemental guidance to Emergency Directive (ED) 21-01, most recently on January 6, 2021. Note: this Activity Alert does not supersede the requirements of ED 21-01 or any supplemental guidance and does not represent formal guidance to federal agencies under ED 21-01.

CISA has determined that this threat poses a grave risk to the Federal Government and state, local, tribal, and territorial governments as well as critical infrastructure entities and other private sector organizations. CISA advises stakeholders to read this Alert and review the enclosed indicators (see Appendix B).

Key Takeaways (updated December 18, 2020)

• This is a patient, well-resourced, and focused adversary that has sustained long duration activity on victim networks.
• CISA is investigating other initial access vectors in addition to the SolarWinds Orion supply chain compromise. 
• Not all organizations that have the backdoor delivered through SolarWinds Orion have been targeted by the adversary with follow-on actions.
• Organizations with suspected compromises need to be highly conscious of operational security, including when engaging in incident response activities and planning and implementing remediation plans. 

(Updated January 8, 2021) For a downloadable list of indicators of compromise (IOCs), see the STIX file, MAR-10318845-1.v1.stix, and MAR-10320115-1.v1.stix.

Technical Details

Overview

CISA is aware of compromises, which began at least as early as March 2020, at U.S. government agencies, critical infrastructure entities, and private sector organizations by an APT actor. This threat actor has demonstrated sophistication and complex tradecraft in these intrusions. CISA expects that removing the threat actor from compromised environments will be highly complex and challenging. This adversary has demonstrated an ability to exploit software supply chains and shown significant knowledge of Windows networks. It is likely that the adversary has additional initial access vectors and TTPs that have not yet been discovered. CISA will continue to update this Alert and the corresponding IOCs as new information becomes available.

Initial Infection Vectors [TA0001]

(Updated January 6, 2021): CISA is investigating incidents that exhibit adversary TTPs consistent with this activity, including some where victims either do not leverage SolarWinds Orion or where SolarWinds Orion was present but where there was no SolarWinds exploitation activity observed. CISA incident response investigations have identified that initial access in some cases was obtained by password guessing [T1101.001], password spraying [T1101.003], and inappropriately secured administrative credentials [T1078] accessible via external remote access services [T1133]. Initial access root cause analysis is still ongoing in a number of response activities and CISA will update this section as additional initial vectors are identified.

Volexity has also reported publicly that they observed the APT using a secret key that the APT previously stole in order to generate a cookie to bypass the Duo multi-factor authentication (MFA) protecting access to Outlook Web App (OWA).[1] Volexity attributes this intrusion to the same activity as the SolarWinds Orion supply chain compromise, and the TTPs are consistent between the two. This observation indicates that there are other initial access vectors beyond SolarWinds Orion, and there may still be others that are not yet known.

SolarWinds Orion Supply Chain Compromise [T1195.002]

SolarWinds Orion is an enterprise network management software suite that includes performance and application monitoring and network configuration management along with several different types of analyzing tools. SolarWinds Orion is used to monitor and manage on-premise and hosted infrastructures. To provide SolarWinds Orion with the necessary visibility into this diverse set of technologies, it is common for network administrators to configure SolarWinds Orion with pervasive privileges, making it a valuable target for adversary activity.

The threat actor has been observed leveraging a software supply chain compromise of SolarWinds Orion products[2] (see Appendix A). The adversary added a malicious version of the binary solarwinds.orion.core.businesslayer.dll into the SolarWinds software lifecycle, which was then signed by the legitimate SolarWinds code signing certificate. This binary, once installed, calls out to a victim-specific avsvmcloud[.]com domain using a protocol designed to mimic legitimate SolarWinds protocol traffic. After the initial check-in, the adversary can use the Domain Name System (DNS) response to selectively send back new domains or IP addresses for interactive command and control (C2) traffic. Consequently, entities that observe traffic from their SolarWinds Orion devices to avsvmcloud[.]com should not immediately conclude that the adversary leveraged the SolarWinds Orion backdoor. Instead, additional investigation is needed into whether the SolarWinds Orion device engaged in further unexplained communications. If additional Canonical Name record (CNAME) resolutions associated with the avsvmcloud[.]com domain are observed, possible additional adversary action leveraging the backdoor has occurred.

Based on coordinated actions by multiple private sector partners, as of December 15, 2020, avsvmcloud[.]com resolves to 20.140.0[.]1, which is an IP address on the Microsoft blocklist. This negates any future use of the implants and would have caused communications with this domain to cease. In the case of infections where the attacker has already moved C2 past the initial beacon, infection will likely continue notwithstanding this action.

SolarWinds Orion typically leverages a significant number of highly privileged accounts and access to perform normal business functions. Successful compromise of one of these systems can therefore enable further action and privileges in any environment where these accounts are trusted.

Anti-Forensic Techniques

The adversary is making extensive use of obfuscation to hide their C2 communications. The adversary is using virtual private servers (VPSs), often with IP addresses in the home country of the victim, for most communications to hide their activity among legitimate user traffic. The attackers also frequently rotate their “last mile” IP addresses to different endpoints to obscure their activity and avoid detection.

FireEye has reported that the adversary is using steganography (Obfuscated Files or Information: Steganography [T1027.003]) to obscure C2 communications.[3] This technique negates many common defensive capabilities in detecting the activity. Note: CISA has not yet been able to independently confirm the adversary’s use of this technique.

According to FireEye, the malware also checks for a list of hard-coded IPv4 and IPv6 addresses—including RFC-reserved IPv4 and IPv6 IP—in an attempt to detect if the malware is executed in an analysis environment (e.g., a malware analysis sandbox); if so, the malware will stop further execution. Additionally, FireEye analysis identified that the backdoor implemented time threshold checks to ensure that there are unpredictable delays between C2 communication attempts, further frustrating traditional network-based analysis.

While not a full anti-forensic technique, the adversary is heavily leveraging compromised or spoofed tokens for accounts for lateral movement. This will frustrate commonly used detection techniques in many environments. Since valid, but unauthorized, security tokens and accounts are utilized, detecting this activity will require the maturity to identify actions that are outside of a user’s normal duties. For example, it is unlikely that an account associated with the HR department would need to access the cyber threat intelligence database.

Taken together, these observed techniques indicate an adversary who is skilled, stealthy with operational security, and is willing to expend significant resources to maintain covert presence.

Privilege Escalation and Persistence [TA0004, TA0003]

(Updated January 6, 2021): The adversary has been observed using multiple persistence mechanisms across a variety of intrusions. CISA has observed the threat actor adding authentication credentials, in the form of assigning tokens and certificates, to existing Azure/Microsoft 365 (M365) application service principals. These additional credentials provide persistence and escalation mechanisms and a programmatic method of interacting with the Microsoft Cloud tenants (often with Microsoft Graph Application Programming Interface [API]) to access hosted resources without significant evidence or telemetry being generated.

(Updated January 6, 2021): Microsoft reported that the actor has added new federation trusts to existing on permises infrastructure, a technique that CISA believes was utilized by a threat actor in an incident to which CISA has responded. Where this technique is used, it is possible that authentication can occur outside of an organization’s known infrastructure and may not be visible to the legitimate system owner. Microsoft has released a query to help identify this activity, as well as a Sentinel detection for identifying changes to the identity federation from a user or application.[4]

User Impersonation

(Updated January 6, 2021): The adversary’s initial objectives, as understood today, appear to be to collect information from victim environments. One method the adversary is accomplishing this objective is by compromising the SAML signing certificate using their escalated Active Directory privileges. Once this is accomplished, the adversary creates unauthorized but valid tokens and presents them to services that trust SAML tokens from the environment. These tokens can then be used to access resources in hosted environments, such as email, for data exfiltration via authorized APIs. During the persistence phase, the additional credentials being attached to service principals obfuscates the activity of user objects, because they appear to be accessed by the individual, and such individual access is normal and not logged in all M365 licensing levels.

CISA has observed in its incident response work adversaries targeting email accounts belonging to key personnel, including IT and incident response personnel.

These are some key functions and systems that commonly use SAML.

• Hosted email services
• Hosted business intelligence applications
• Travel systems
• Timecard systems
• File storage services (such as SharePoint and OneDrive)

(New January 6, 2021): Detection: Identifying Compromised Azure/M365 Resources

CISA created Sparrow.ps1[5] to help detect possible compromised accounts and applications in the Azure/M365 environment. Sparrow is intended for use by incident responders and focuses on the narrow scope of user and application activity endemic to identity- and authentication-based attacks seen recently in multiple sectors. It is neither comprehensive nor exhaustive of available data and is intended to narrow a larger set of available investigation modules and telemetry to those specific to recent intrusions on federated identity sources and applications. Sparrow can be found on CISA’s Github page at https://github.com/cisagov/Sparrow.

Detection: Impossible Logins

The adversary is using a complex network of IP addresses to obscure their activity, which can result in a detection opportunity referred to as “impossible travel.” Impossible travel occurs when a user logs in from multiple IP addresses that are a significant geographic distance apart (i.e., a person could not realistically travel between the geographic locations of the two IP addresses during the time period between the logins). Note: implementing this detection opportunity can result in false positives if legitimate users apply virtual private network (VPN) solutions before connecting into networks.

Detection: Impossible Tokens

The following conditions may indicate adversary activity.

• (Updated January 6, 2021): Most organizations have SAML tokens with 1-hour validity periods. Long SAML token validity durations, such as 24 hours, could be unusual. Exact values (measured in precise seconds) is also considered unusual.
• The SAML token contains different timestamps, including the time it was issued and the last time it was used. A token having the same timestamp for when it was issued and when it was used is not indicative of normal user behavior as users tend to use the token within a few seconds but not at the exact same time of issuance.
• A token that does not have an associated login with its user account within an hour of the token being generated also warrants investigation.
• (New January 6, 2021): Tokens with missing or unusual MFA details, when MFA is enforced, is considered an anoamaoly and should be investigated. This requires correlation of identity provider (iDP) logs with cloud access; differences in claims indicate maninpulated values. All claims should have a corresponding iDP entry.

(New December 21, 2020): see the National Security Agency (NSA) Cybersecurity Advisory: Detecting Abuse of Authentication Mechanisms for additional detection methods as well as mitigation recommendations.

Operational Security

Due to the nature of this pattern of adversary activity—and the targeting of key personnel, incident response staff, and IT email accounts—discussion of findings and mitigations should be considered very sensitive, and should be protected by operational security measures. An operational security plan needs to be developed and socialized, via out-of-band communications, to ensure all staff are aware of the applicable handling caveats.

Operational security plans should include:

• Out-of-band communications guidance for staff and leadership;
• An outline of what “normal business” is acceptable to be conducted on the suspect network;
• A call tree for critical contacts and decision making; and
• Considerations for external communications to stakeholders and media.

MITRE ATT&CK® Techniques

CISA assesses that the threat actor engaged in the activities described in this Alert uses the below-listed ATT&CK techniques.

• Query Registry [T1012]
• Obfuscated Files or Information [T1027]
• Obfuscated Files or Information: Steganography [T1027.003]
• Process Discovery [T1057]
• Indicator Removal on Host: File Deletion [T1070.004]
• Application Layer Protocol: Web Protocols [T1071.001]
• Application Layer Protocol: DNS [T1071.004]
• File and Directory Discovery [T1083]
• Ingress Tool Transfer [T1105]
• Data Encoding: Standard Encoding [T1132.001]
• Supply Chain Compromise: Compromise Software Dependencies and Development Tools [T1195.001]
• Supply Chain Compromise: Compromise Software Supply Chain [T1195.002]
• Software Discovery [T1518]
• Software Discovery: Security Software [T1518.001]
• Create or Modify System Process: Windows Service [T1543.003]
• Subvert Trust Controls: Code Signing [T1553.002]
• Dynamic Resolution: Domain Generation Algorithms [T1568.002]
• System Services: Service Execution [T1569.002]
• Compromise Infrastructure [T1584]

Mitigations

(Updated January 6, 2021) SolarWinds Orion Owners

Networks with SolarWinds Orion products will generally fall into one of three categories. (Note: for the purposes of mitigation analysis, a network is defined as any computer network with hosts that share either a logical trust or any account credentials with SolarWinds Orion.)

• Category 1 includes those who do not have the identified malicious binary code on their network and can forensically confirm that the binary was never present on their systems. This includes networks that do not, and never did, utilize the affected versions of SolarWinds Orion products (see Appendix A).
• Category 2 includes networks where the presence of the malicious binary has been identified—with or without beaconing to avsvmcloud[.]com. This includes networks that previously utilized affected versions of SolarWinds Orion but where the organization has forensically verified (through comprehensive network monitoring and analysis) that platforms running the affected software either:
   
  1. Had no beaconing, or
  2. Only beaconed to avsvmcloud[.]com and have not had any secondary C2 activity to a separate domain or IP address or other adversary activity or secondary actions on objectives (AOOs),[6] such as SAML token abuse.
      
• Category 2 organizations, after conducting appropriate forensic analysis to ensure they only have category 2 activity, can rebuild the platform, harden the configuration based on SolarWinds secure configuration guidelines, and resume use as determined by and consistent with their thorough risk evaluation. For entities not subject to ED 21-01, this can be accomplished by following the steps below. Federal agencies subject to ED 21-01 must follow the appropriate steps as outlined in the effective ED 21-01 supplemental guidance.
   
  1. Denying all incoming and outgoing (any:any) communications outside of the organization’s device network management enclave, with additional assurance that communications to the public internet to and from hosts running SolarWinds Orion products has been blocked.
  2. Cloud instances of Orion should only monitor cloud resources in that cloud infrastructure.
  3. On-premises instances of Orion should not be permissioned with any cloud/hosted identity accounts.
  4. Restoration of SolarWinds may be done from the legacy database following the SolarWinds restore guidance (http://solarwinds.com/upgrading-your-environment). Restoration for affected versions will differ from restoration for unaffected versions—agencies must ensure that they are following the correct restoration guidance.
  5. Before building SolarWinds:
     1. All account credentials, or other shared secrets (e.g., Simple Network Management Protocol [SNMP] strings) that are or had been utilized by the affected SolarWinds Orion device being rebuilt should be changed.
     2. Enable MFA for these credentials, whenever possible.
     3. Provide service accounts with the minimum privilege necessary for the role performed, whenever possible.
     4. For accounts where MFA is not possible  (e.g., service accounts), use randomly generated long and complex passwords (greater than 25 characters) and implement a maximum 90-day rotation policy for these passwords.
     5. Remove all inbound trust relationships to the SolarWinds Orion device being rebuilt.
  6. Re-building a SolarWinds Orion Platform to at least version 2020.2.1 HF2 and updating the host to the latest supported build, at least Windows 2016.
  7. Following the SolarWinds secure configuration (hardening) guidelines provided by the vendor, which can be found at: https://documentation.solarwinds.com/en/Success_Center/orionplatform/content/core-secure-configuration.htm. CISA does not recommend configuring the SolarWinds software to implement SAML-based authentication that relies on Microsoft’s Active Directory Federated Services if it has not already been configured to leverage SAML. This configuration is currently being exploited by the threat actor with this activity.
  8. Configuring logging to ensure that all logs on the host operating system and SolarWinds platform are being captured and stored for at least 180 days.
  9. Configure logging to ensure that all logs from the host OS, SolarWinds platform, and associated network logs are being captured and stored for at least 180 days in a separate, centralized log aggregation capability.
  10. Implementing subsequent SolarWinds Orion Platform updates. CISA recommends installing all updates within 48 hours of release. 
       
• Category 3 includes those networks that used affected versions of SolarWinds Orion and have evidence of follow-on threat actor activity, such as binary beaconing to avsvmcloud[.]com and secondary C2 activity to a separate domain or IP address (typically but not exclusively returned in avsvmcloud[.]com CNAME responses). Additionally, organizations that have observed communications with avsvmcloud[.]com that appear to suddenly cease prior to December 14, 2020—not due to an action taken by their network defenders—fall into this category. Assume the environment has been compromised, and initiate incident response procedures immediately. Recovery and remediation of Category 3 activity requires a complex reconstitution and mitigation plan, which may include comprehensively rebuilding the environment. This should be coordinated with an organization’s leadership and incident response team.

Compromise Mitigations

(Updated January 6, 2021): If the adversary has compromised administrative level credentials in an environment—or if organizations identify SAML abuse in the environment, simply mitigating individual issues, systems, servers, or specific user accounts will likely not lead to the adversary’s removal from the network. In such cases, organizations should consider the entire identity trust store as compromised. In the event of a total identity compromise, a full reconstitution of identity and trust services is required to successfully remediate. In this reconstitution, it bears repeating that this threat actor is among the most capable, and in many cases, a full rebuild of the environment is the safest action. A Microsoft blog post, Advice for incident responders on recovery from systemic identity compromises outlines processes and procedures needed to remediate this type of activity and retain administrative control of an environment. In addition to the recommendations in this blog post, CISA recommends the following actions:

1. Take actions to remediate kerberoasting, including, as necessary or appropriate, engaging with a 3rd party with experience eradicating APTs from enterprise networks. For Windows environments, refer to the following:
   1. See Microsoft’s documentation on kerberoasting: https://techcommunity.microsoft.com/t5/microsoft-security-and/detecting-ldap-based-kerberoasting-with-azure-atp/ba-p/462448.
   2. Change all account credentials, or other shared secrets (e.g., SNMP strings) that were potentially exposed:
      1. Enable MFA for these credentials, whenever possible;
      2. Provide service accounts with the minimum level of privilege necessary for the role performed, whenever possible; and
      3. For accounts where MFA is not possible, require use of randomly generated long and complex passwords (greater than 25 characters) and implement a maximum 90-day rotation policy for these passwords.
   3. Replace the user accounts with a Group Managed Service Account (gMSA). See https://docs.microsoft.com/en-us/windows-server/security/group-managed-service-accounts/group-managed-service-accounts-overview, and Implement Group Managed Service Accounts: https://docs.microsoft.com/en-us/windows-server/security/group-managed-service-accounts/group-managed-service-accounts-overview.
   4. Set account options for service accounts to support AES256_CTS_HMAC_SHA1_96 and not support DES, RC4, or AES128 bit encryption
   5. Define the Security Policy setting, for Network Security: Configure Encryption types allowed for Kerberos. Set the allowable encryption types to AES256_HMAC_SHA1 and Future encryption types. https://docs.microsoft.com/en-us/windows/security/threat-protection/security-policy-settings/network-security-configure-encryption-types-allowed-for-kerberos
   6. See Microsoft’s documentation on how to reset the Kerberos Ticket Granting Ticket password, twice: https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/ad-forest-recovery-resetting-the-krbtgt-password.

SolarWinds Orion Specific Mitigations

The following mitigations apply to networks using the SolarWinds Orion product. This includes any information system that is used by an entity or operated on its behalf.

Organizations that have the expertise to take the actions in Step 1 immediately should do so before proceeding to Step 2. Organizations without this capability should proceed to Step 2. Federal civilian executive branch agencies should ignore the below and refer instead to Emergency Directive 21-01 (and forthcoming associated guidance) for mitigation steps.

• Step 1
  • Forensically image system memory and/or host operating systems hosting all instances of affected versions of SolarWinds Orion. Analyze for new user or service accounts, privileged or otherwise.
  • Analyze stored network traffic for indications of compromise, including new external DNS domains to which a small number of agency hosts (e.g., SolarWinds systems) have had connections.
• Step 2
  • Affected organizations should immediately disconnect or power down affected all instances of affected versions of SolarWinds Orion from their network.
  • Additionally:
    • Block all traffic to and from hosts, external to the enterprise, where any version of SolarWinds Orion software has been installed.
    • Identify and remove all threat actor-controlled accounts and identified persistence mechanisms.  
• Step 3  
  • Only after all known threat actor-controlled accounts and persistence mechanisms have been removed:
    • Treat all hosts monitored by the SolarWinds Orion monitoring software as compromised by threat actors and assume that the threat actor has deployed further persistence mechanisms.
    • Rebuild hosts monitored by the SolarWinds Orion monitoring software using trusted sources.
    • Reset all credentials used by or stored in SolarWinds software. Such credentials should be considered compromised.
• (New December 19, 2020) For all network devices (routers, switches, firewalls, etc.) managed by affected SolarWinds servers that also have indications of additional adversary activity, CISA recommends the following steps:
  • Device configurations
    • Audit all network device configurations, stored or managed on the SolarWinds monitoring server, for signs of unauthorized or malicious configuration changes.
    • Audit the configurations found on network devices for signs of unauthorized or malicious configuration changes. Organizations should ensure they audit the current network device running configuration and any local configurations that could be loaded at boot time.
  • Credential and security information reset
    • Change all credentials being used to manage network devices, to include keys and strings used to secure network device functions (SNMP strings/user credentials, IPsec/IKE preshared keys, routing secrets, TACACS/RADIUS secrets, RSA keys/certificates, etc.).
  • Firmware and software validation
    • Validate all network device firmware/software which was stored or managed on the SolarWinds monitoring server. Cryptographic hash verification should be performed on such firmware/software and matched against known good hash values from the network vendor. CISA recommends that, if possible, organizations download known good versions of firmware.
• For network devices managed by the SolarWinds monitoring server, the running firmware/software should be checked against known good hash values from the network vendor. CISA recommends that, if possible, organizations re-upload known good firmware/software to managed network devices and perform a reboot.

See Joint Alert on Technical Approaches to Uncovering and Remediating Malicious Activity for more information on incident investigation and mitigation steps based on best practices.

CISA will update this Alert, as information becomes available and will continue to provide technical assistance, upon request, to affected entities as they work to identify and mitigate potential compromises.

Contact Information

CISA encourages recipients of this report to contribute any additional information that they may have related to this threat. For any questions related to this report, please contact CISA at

• 1-888-282-0870 (From outside the United States: +1-703-235-8832)
• central@cisa.dhs.gov (UNCLASS)
• us-cert@dhs.sgov.gov (SIPRNET)
• us-cert@dhs.ic.gov (JWICS)

CISA encourages you to report any suspicious activity, including cybersecurity incidents, possible malicious code, software vulnerabilities, and phishing-related scams. Reporting forms can be found on the CISA/US-CERT homepage at http://www.us-cert.cisa.gov/.

Appendix A: Affected SolarWinds Orion Products

Table 1 identifies recent versions of SolarWinds Orion Platforms and indicates whether they have been identified as having the Sunburst backdoor present. (Updated January 6, 2021: added SHA-1 and MD5 hashes to table 1; updated SHA-256 hash for version 2019.4 HF6).

Table 1: Affected SolarWinds Orion Products

Appendix B: Indicators of Compromise

Due to the operational security posture of the adversary, most observable IOCs are of limited utility; however, they can be useful for quick triage. Below is a compilation of IOCs from a variety of public sources provided for convenience. CISA will be updating this list with CISA developed IOCs as our investigations evolve. Note: removed two IOCs (12.227.230[.]4, 65.153.203[.]68) and corrected typo, updated December 19, 2020; added multiple new IOCs on January 6, 2021 (new IOCs added are at the bottom of the table); corrected typos, added new IOC, and deleted duplicate hash on January 7, 2021.

Table 2: Indicators of Compromise

References

• [1] Volexity: Dark Halo Leverages SolarWinds Compromise to Breach Organizations
• [2] SolarWinds Security Advisory
• [3] FireEye: Highly Evasive Attacker Leverages SolarWinds Supply Chain to Compromise Multiple Global Victims With SUNBURST Backdoor
• [4] GitHub: Azure / Azure-Sentinel - ADFSDomainTrustMods.yaml
• [5] GitHub: CISA: Sparrow
• [6] Lockheed Martin: Seven Ways to Apply the Cyber Kill Chain with a Threat Intelligence Platfor

Revisions

• Initial version: December 17, 2020
• December 18, 2020: Updated note regarding initial vectors and key takeaways.
• December 19, 2020: Updated mitigation guidance, indicators of compromise table, and provided a downloadable STIX file of the IOCs.
• December 21, 2020: Added reference to NSA Cybersecurity Advisory: Detecting Abuse of Authentication Methods
• December 23, 2020: Added link to CISA.gov/supply-chain-compromise
• January 06, 2021: Updated Initial Access Vectors, Mitigations, and IOCs
• January 07, 2021: Updated IOCs
• Febraury 08, 2021: Updated IOCs

AA20-345A: Cyber Actors Target K-12 Distance Learning Education to Cause Disruptions and Steal Data
Original release date: December 10, 2020

Summary

This Joint Cybersecurity Advisory was coauthored by the Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), and the Multi-State Information Sharing and Analysis Center (MS-ISAC).

The FBI, CISA, and MS-ISAC assess malicious cyber actors are targeting kindergarten through twelfth grade (K-12) educational institutions, leading to ransomware attacks, the theft of data, and the disruption of distance learning services. Cyber actors likely view schools as targets of opportunity, and these types of attacks are expected to continue through the 2020/2021 academic year. These issues will be particularly challenging for K-12 schools that face resource limitations; therefore, educational leadership, information technology personnel, and security personnel will need to balance this risk when determining their cybersecurity investments.

Click here for a PDF version of this report.

Technical Details

As of December 2020, the FBI, CISA, and MS-ISAC continue to receive reports from K-12 educational institutions about the disruption of distance learning efforts by cyber actors.

Ransomware

The FBI, CISA, and MS-ISAC have received numerous reports of ransomware attacks against K-12 educational institutions. In these attacks, malicious cyber actors target school computer systems, slowing access, and—in some instances—rendering the systems inaccessible for basic functions, including distance learning. Adopting tactics previously leveraged against business and industry, ransomware actors have also stolen—and threatened to leak—confidential student data to the public unless institutions pay a ransom.

According to MS-ISAC data, the percentage of reported ransomware incidents against K-12 schools increased at the beginning of the 2020 school year. In August and September, 57% of ransomware incidents reported to the MS-ISAC involved K-12 schools, compared to 28% of all reported ransomware incidents from January through July.

The five most common ransomware variants identified in incidents targeting K-12 schools between January and September 2020—based on open source information as well as victim and third-party incident reports made to MS-ISAC—are Ryuk, Maze, Nefilim, AKO, and Sodinokibi/REvil.

Malware

Figure 1 identifies the top 10 malware strains that have affected state, local, tribal, and territorial (SLTT) educational institutions over the past year (up to and including September 2020). Note: These malware variants are purely opportunistic as they not only affect educational institutions but other organizations as well.

ZeuS and Shlayer are among the most prevalent malware affecting K-12 schools.

• ZeuS is a Trojan with several variants that targets Microsoft Windows operating systems. Cyber actors use ZeuS to infect target machines and send stolen information to command-and-control servers.
• Shlayer is a Trojan downloader and dropper for MacOS malware. It is primarily distributed through malicious websites, hijacked domains, and malicious advertising posing as a fake Adobe Flash updater. Note: Shlayer is the only malware of the top 10 that targets MacOS; the other 9 affect Microsoft Windows operating systems

Figure 1: Top 10 malware affecting SLTT educational institutions

 
Distributed Denial-of-Service Attacks

Cyber actors are causing disruptions to K-12 educational institutions—including third-party services supporting distance learning—with distributed denial-of-service (DDoS) attacks,  which temporarily limit or prevent users from conducting daily operations. The availability of DDoS-for-hire services provides opportunities for any motivated malicious cyber actor to conduct disruptive attacks regardless of experience level. Note: DDoS attacks overwhelm servers with a high level of internet traffic originating from many different sources, making it impossible to mitigate at a single source.

Video Conference Disruptions

Numerous reports received by the FBI, CISA, and MS-ISAC since March 2020 indicate uninvited users have disrupted live video-conferenced classroom sessions. These disruptions have included verbally harassing students and teachers, displaying pornography and/or violent images, and doxing meeting attendees (Note: doxing is the act of compiling or publishing personal information about an individual on the internet, typically with malicious intent). To enter classroom sessions, uninvited users have been observed:

• Using student names to trick hosts into accepting them into class sessions, and
• Accessing meetings from either publicly available links or links shared with outside users (e.g., students sharing links and/or passwords with friends).

Video conference sessions without proper control measures risk disruption or compromise of classroom conversations and exposure of sensitive information.

Additional Risks and Vulnerabilities

In addition to the recent reporting of distance learning disruptions received by the FBI, CISA, and MS-ISAC, malicious cyber actors are expected to continue seeking opportunities to exploit the evolving remote learning environment.

Social Engineering

Cyber actors could apply social engineering methods against students, parents, faculty, IT personnel, or other individuals involved in distance learning. Tactics, such as phishing, trick victims into revealing personal information (e.g., password or bank account information) or performing a task (e.g., clicking on a link). In such scenarios, a victim could receive what appears to be legitimate email that:

• Requests personally identifiable information (PII) (e.g., full name, birthdate, student ID),
• Directs the user to confirm a password or personal identification number (PIN),
• Instructs the recipient to visit a website that is compromised by the cyber actor, or
• Contains an attachment with malware.

Cyber actors also register web domains that are similar to legitimate websites in an attempt to capture individuals who mistype URLs or click on similar looking URLs. These types of attacks are referred to as domain spoofing or homograph attacks. For example, a user wanting to access www.cottoncandyschool.edu could mistakenly click on www.cottencandyschool.edu (changed “o” to an “e”) or www.cottoncandyschoo1.edu (changed letter “l” to a number “1”) (Note: this is a fictitious example to demonstrate how a user can mistakenly click and access a website without noticing subtle changes in website URLs). Victims believe they are on a legitimate website when, in reality, they are visiting a site controlled by a cyber actor.

Technology Vulnerabilities and Student Data

Whether as collateral for ransomware attacks or to sell on the dark web, cyber actors may seek to exploit the data-rich environment of student information in schools and education technology (edtech) services. The need for schools to rapidly transition to distance learning likely contributed to cybersecurity gaps, leaving schools vulnerable to attack. In addition, educational institutions that have outsourced their distance learning tools may have lost visibility into data security measures. Cyber actors could view the increased reliance on—and sharp usership growth in—these distance learning services and student data as lucrative targets.

Open/Exposed Ports

The FBI, CISA, and MS-ISAC frequently see malicious cyber actors exploiting exposed Remote Desktop Protocol (RDP) services to gain initial access to a network and, often, to manually deploy ransomware. For example, cyber actors will attack ports 445 (Server Message Block [SMB]) and 3389 (RDP) to gain network access. They are then positioned to move laterally throughout a network (often using SMB), escalate privileges, access and exfiltrate sensitive information, harvest credentials, or deploy a wide variety of malware. This popular attack vector allows cyber actors to maintain a low profile, as they are using a legitimate network service that provides them with the same functionality as any other remote user.

End-of-Life Software

End-of-Life (EOL) software is regularly exploited by cyber actors—often to gain initial access, deface websites, or further their reach in a network. Once a product reaches EOL, customers no longer receive security updates, technical support, or bug fixes. Unpatched and vulnerable servers are likely to be exploited by cyber actors, hindering an organization’s operational capacity.

Mitigations

Plans and Policies

The FBI and CISA encourage educational providers to maintain business continuity plans—the practice of executing essential functions through emergencies (e.g., cyberattacks)—to minimize service interruptions. Without planning, provision, and implementation of continuity principles, institutions may be unable to continue teaching and administrative operations. Evaluating continuity and capability will help identify potential operational gaps. Through identifying and addressing these gaps, institutions can establish a viable continuity program that will help keep them functioning during cyberattacks or other emergencies. The FBI and CISA suggest K-12 educational institutions review or establish patching plans, security policies, user agreements, and business continuity plans to ensure they address current threats posed by cyber actors.

Network Best Practices

• Patch operating systems, software, and firmware as soon as manufacturers release updates.
• Check configurations for every operating system version for educational institution-owned assets to prevent issues from arising that local users are unable to fix due to having local administration disabled.
• Regularly change passwords to network systems and accounts and avoid reusing passwords for different accounts.
• Use multi-factor authentication where possible.
• Disable unused remote access/RDP ports and monitor remote access/RDP logs.
• Implement application and remote access allow listing to only allow systems to execute programs known and permitted by the established security policy.
• Audit user accounts with administrative privileges and configure access controls with least privilege in mind.
• Audit logs to ensure new accounts are legitimate.
• Scan for open or listening ports and mediate those that are not needed.
• Identify critical assets such as student database servers and distance learning infrastructure; create backups of these systems and house the backups offline from the network.
• Implement network segmentation. Sensitive data should not reside on the same server and network segment as the email environment.
• Set antivirus and anti-malware solutions to automatically update; conduct regular scans.

User Awareness Best Practices

• Focus on awareness and training. Because end users are targeted, make employees and students aware of the threats—such as ransomware and phishing scams—and how they are delivered. Additionally, provide users training on information security principles and techniques as well as overall emerging cybersecurity risks and vulnerabilities.
• Ensure employees know who to contact when they see suspicious activity or when they believe they have been a victim of a cyberattack. This will ensure that the proper established mitigation strategy can be employed quickly and efficiently.
• Monitor privacy settings and information available on social networking sites.

Ransomware Best Practices

The FBI and CISA do not recommend paying ransoms. Payment does not guarantee files will be recovered. It may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. However, regardless of whether your organization decided to pay the ransom, the FBI urges you to report ransomware incidents to your local FBI field office. Doing so provides the FBI with the critical information they need to prevent future attacks by identifying and tracking ransomware attackers and holding them accountable under U.S. law.

In addition to implementing the above network best practices, the FBI and CISA also recommend the following:

• Regularly back up data, air gap, and password protect backup copies offline.
• Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, secure location.

Denial-of-Service Best Practices

• Consider enrolling in a denial-of-service mitigation service that detects abnormal traffic flows and redirects traffic away from your network.
• Create a partnership with your local internet service provider (ISP) prior to an event and work with your ISP to control network traffic attacking your network during an event.
• Configure network firewalls to block unauthorized IP addresses and disable port forwarding.

Video-Conferencing Best Practices

• Ensure participants use the most updated version of remote access/meeting applications.
• Require passwords for session access.
• Encourage students to avoid sharing passwords or meeting codes.
• Establish a vetting process to identify participants as they arrive, such as a waiting room.
• Establish policies to require participants to sign in using true names rather than aliases.
• Ensure only the host controls screensharing privileges.
• Implement a policy to prevent participants from entering rooms prior to host arrival and to prevent the host from exiting prior to the departure of all participants.

Edtech Implementation Considerations

• When partnering with third-party and edtech services to support distance learning, educational institutions should consider the following:
• The service provider’s cybersecurity policies and response plan in the event of a breach and their remediation practices:
  • How did the service provider resolve past cyber incidents? How did their cybersecurity practices change after these incidents?
• The provider’s data security practices for their products and services (e.g., data encryption in transit and at rest, security audits, security training of staff, audit logs);
• The provider’s data maintenance and storage practices (e.g., use of company servers, cloud storage, or third-party services);
• Types of student data the provider collects and tracks (e.g., PII, academic, disciplinary, medical, biometric, IP addresses);
• Entities to whom the provider will grant access to the student data (e.g., vendors);
• How the provider will use student data (e.g., will they sell it to—or share it with—third parties for service enhancement, new product development, studies, marketing/advertising?);
• The provider’s de-identification practices for student data; and
• The provider’s policies on data retention and deletion.

Malware Defense

Table 1 identifies CISA-created Snort signatures, which have been successfully used to detect and defend against related attacks, for the malware variants listed below. Note: the listing is not fully comprehensive and should not be used at the exclusion of other detection methods.

Table 1: Malware signatures

Contact Information

To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at www.fbi.gov/contact-us/field. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting organization; and a designated point of contact.

To request incident response resources or technical assistance related to these threats, contact CISA at Central@cisa.gov.

Resources

MS-ISAC membership is open to employees or representatives from all public K-12 education entities in the United States. The MS-ISAC provides multiple cybersecurity services and benefits to help K-12 education entities increase their cybersecurity posture. To join, visit https://learn.cisecurity.org/ms-isac-registration.

• CISA Telework Guidance and Resources
• CISA Cybersecurity Recommendations and Tips for Schools Using Video Conferencing
• CISA Ransomware Publications
• CISA Emergency Services Sector Continuity Planning Suite
• CISA-MS-ISAC Joint Ransomware Guide
• CISA Tip: Avoiding Social Engineering and Phishing Attacks
• CISA Tip: Understanding Patches
• CISA and CYBER.ORG “Cyber Safety Video Series” for K-12 students and educators
• FBI PSA: “High-Impact Ransomware Attacks Threaten U.S. Businesses and Organizations

Note: contact your local FBI field office (www.fbi.gov/contact-us/field) for additional FBI products on ransomware, edtech, and cybersecurity for educational institutions.

Revisions

• Initial Version: December 10, 2020

AA20-336A: Advanced Persistent Threat Actors Targeting U.S. Think Tanks
Original release date: December 1, 2020

Summary

This Advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework. See the ATT&CK for Enterprise for all referenced threat actor tactics and techniques.

The Cybersecurity and Infrastructure Security Agency (CISA) and the Federal Bureau of Investigation (FBI) have observed persistent continued cyber intrusions by advanced persistent threat (APT) actors targeting U.S. think tanks. This malicious activity is often, but not exclusively, directed at individuals and organizations that focus on international affairs or national security policy.[1] The following guidance may assist U.S. think tanks in developing network defense procedures to prevent or rapidly detect these attacks.

APT actors have relied on multiple avenues for initial access. These have included low-effort capabilities such as spearphishing emails and third-party message services directed at both corporate and personal accounts, as well as exploiting vulnerable web-facing devices and remote connection capabilities. Increased telework during the COVID-19 pandemic has expanded workforce reliance on remote connectivity, affording malicious actors more opportunities to exploit those connections and to blend in with increased traffic. Attackers may leverage virtual private networks (VPNs) and other remote work tools to gain initial access or persistence on a victim’s network. When successful, these low-effort, high-reward approaches allow threat actors to steal sensitive information, acquire user credentials, and gain persistent access to victim networks.

Given the importance that think tanks can have in shaping U.S. policy, CISA and FBI urge individuals and organizations in the international affairs and national security sectors to immediately adopt a heightened state of awareness and implement the critical steps listed in the Mitigations section of this Advisory.

Click here for a PDF version of this report.

Technical Details

ATT&CK Profile

CISA created the following MITRE ATT&CK profile to provide a non-exhaustive list of tactics, techniques, and procedures (TTPs) employed by APT actors to break through think tanks’ defenses, conduct reconnaissance in their environments, exfiltrate proprietary or confidential information, and execute effects on targets. These TTPs were included based upon closed reporting on APT actors that are known to target think tanks or based upon CISA incident response data.

• Initial Access [TA0001]
  • Valid Accounts [T1078]
  • Valid Accounts: Cloud Accounts [T1078.004]
  • External Remote Services [T1133]
  • Drive-by Compromise [T1189]
  • Exploit Public-Facing Application [T1190]
    • Supply Chain Compromise: Compromise Software Supply Chain [T1195.002]
    • Trusted Relationship [T1199]
    • Phishing: Spearphishing Attachment [T1566.001]
    • Phishing: Spearphishing Link [T1566.002]
    • Phishing: Spearphishing via Service [T1566.003]
• Execution [TA0002]
  • Windows Management Instrumentation [T1047]
  • Scheduled Task/Job: Scheduled Task [T1053.005]
  • Command and Scripting Interpreter: PowerShell [T1059.001]
  • Command and Scripting Interpreter: Windows Command Shell [T1059.003]
  • Command and Scripting Interpreter: Unix Shell [T1059.004]
  • Command and Scripting Interpreter: Visual Basic [T1059.005]
  • Command and Scripting Interpreter: Python [T1059.006]
  • Native API [T1106]
  • Exploitation for Client Execution [T1203]
  • User Execution: Malicious Link [T1204.001]
  • User Execution: Malicious File [T1204.002]
  • Inter-Process Communication: Dynamic Data Exchange [T1559.002]
  • System Services: Service Execution [T1569.002]
• Persistence [TA0003]
  • Boot or Logon Initialization Scripts: Logon Script (Windows) [T1037.001]
  • Scheduled Task/Job: Scheduled Task [T1053.005]
  • Account Manipulation: Exchange Email Delegate Permissions [T1098.002]
  • Create Account: Local Account [T1136.001]
  • Office Application Startup: Office Test [T1137.002]
  • Office Application Startup: Outlook Home Page [T1137.004]
  • Browser Extensions [T1176]
  • BITS Jobs [T1197]
  • Server Software Component: Web Shell [T1505.003]
  • Pre-OS Boot: Bootkit [T1542.003]
  • Create or Modify System Process: Windows Service [T1543.003]
  • Event Triggered Execution: Change Default File Association [T1546.001]
  • Event Triggered Execution: Windows Management Instrumentation Event Subscription [T1546.003]
  • Event Triggered Execution: Accessibility Features [T1546.008]
  • Event Triggered Execution: Component Object Model Hijacking [T1546.015]
  • Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder [T1547.001]
  • Boot or Logon Autostart Execution: Shortcut Modification [T1547.009]
• Privilege Escalation [TA0004]
  • Process Injection [T1055]
  • Process Injection: Process Hollowing [T1055.012]
  • Exploitation for Privilege Escalation [T1068]
  • Access Token Manipulation: Token Impersonation/Theft [T1134.001]
  • Event Triggered Execution: Accessibility Features [T1546.008]
  • Boot or Logon Autostart Execution: Shortcut Modification [T1547.009]
  • Abuse Elevation Control Mechanism: Bypass User Access Control [T1548.002]
  • Hijack Execution Flow: DLL Side-Loading [T1574.002]
• Defense Evasion [TA0005]
  • Rootkit [T1014]
  • Obfuscated Files or Information: Binary Padding [T1027.001]
  • Obfuscated Files or Information: Software Packing [T1027.002]
  • Obfuscated Files or Information: Steganography [T1027.003]
  • Obfuscated Files or Information: Indicator Removal from Tools [T1027.005]
  • Masquerading: Match Legitimate Name or Location [T1036.005]
  • Indicator Removal on Host: Clear Windows Event Logs [T1070.001]
  • Indicator Removal on Host: Clear Command History [1070.003]
  • Indicator Removal on Host: File Deletion [T1070.004]
  • Indicator Removal on Host: Timestomp [T1070.006]
  • Modify Registry [T1112]
  • Deobfuscate/Decode Files or Information [T1140]
  • Exploitation for Defense Evasion [T1211]
  • Signed Binary Proxy Execution: Compiled HTML File [T1218.001]
  • Signed Binary Proxy Execution: Mshta [T1218.005]
  • Signed Binary Proxy Execution: Rundll32 [T1218.011]
  • Template Injection [T1221]
  • Execution Guardrails: Environmental Keying [T1480.001]
  • Abuse Elevation Control Mechanism: Bypass User Access Control [T1548.002]
  • Use Alternate Authentication Material: Application Access Token [T1550.001]
  • Subvert Trust Controls: Code Signing [T1553.002]
  • Impair Defenses: Disable or Modify Tools [T1562.001]
  • Impair Defenses: Disable or Modify System Firewall [T1562.004]
  • Hide Artifacts: Hidden Files and Directories [T1564.001]
  • Hide Artifacts: Hidden Window [T1564.003]
• Credential Access [TA0006]
  • OS Credential Dumping: LSASS Memory [T1003.001]
  • OS Credential Dumping: Security Account Manager [T1003.002]
  • OS Credential Dumping: NTDS [T1003.003]
  • OS Credential Dumping: LSA Secrets [T1003.004]
  • OS Credential Dumping: Cached Domain Credentials [T1003.005]
  • Network Sniffing [T1040]
  • Input Capture: Keylogging [T1056.001]
  • Brute Force: Password Cracking [T1110.002]Brute Force: Password Spraying [T1110.003]
  • Forced Authentication [T1187]
  • Steal Application Access Token [T1528]
  • Unsecured Credentials: Credentials in Files [T1552.001]
  • Unsecured Credentials: Group Policy Preferences [T1552.006]
  • Credentials from Password Stores: Credentials from Web Browsers [T1555.003]
• Discovery [TA0007]
  • System Service Discovery [T1007]
  • Query Registry [T1012]
  • System Network Configuration Discovery [T1016]
  • Remote System Discovery [T1018]
  • System Owner/User Discovery [T1033]
  • Network Sniffing [T1040]
  • Network Service Scanning [T1046]
  • System Network Connections Discovery [T1049]
  • Process Discovery [T1057]
  • Permission Groups Discovery: Local Groups [T1069.001]
  • Permission Groups Discovery: Domain Groups [T1069.002]
  • System Information Discovery [T1082]
  • File and Directory Discovery [T1083]
  • Account Discovery: Local Account [T1087.001]
  • Account Discovery: Domain Account [T1087.002]
  • Peripheral Device Discovery [T1120]
  • Network Share Discovery [T1135]
  • Password Policy Discovery [T1201]
  • Software Discovery: Security Software Discovery [T1518.001]
• Lateral Movement [TA0008]
  • Remote Services: Remote Desktop Protocol [T1021.001]
  • Remote Services: SSH [T1021.004]
  • Taint Shared Content [T1080]
  • Replication Through Removable Media [T1091]
  • Exploitation of Remote Services [T1210]
  • Use Alternate Authentication Material: Pass the Hash [T1550.002]
  • Use Alternate Authentication Material: Pass the Ticket [T1550.003]
• Collection [TA0009]
  • Data from Local System [T1005]
  • Data from Removable Media [T1025]
  • Data Staged: Local Data Staging [T1074.001]
  • Screen Capture [T1113]
  • Email Collection: Local Email Collection [T1114.001]
  • Email Collection: Remote Email Collection [T1114.002]
  • Automated Collection [T1119]
  • Audio Capture [T1123]
  • Data from Information Repositories: SharePoint [T1213.002]
  • Archive Collected Data: Archive via Utility [T1560.001]
  • Archive Collected Data: Archive via Custom Method [T1560.003]
• Command and Control [TA0011]
  • Data Obfuscation: Junk Data [T1001.001]
  • Fallback Channels [T1008]
  • Application Layer Protocol: Web Protocols [T1071.001]
  • Application Layer Protocol: File Transfer Protocols [T1071.002]
  • Application Layer Protocol: Mail Protocols [T1071.003]
  • Application Layer Protocol: DNS [T1071.004]
  • Proxy: External Proxy [T1090.002]
  • Proxy: Multi-hop Proxy [T1090.003]
  • Proxy: Domain Fronting [T1090.004]
  • Communication Through Removable Media [T1092]
  • Non-Application Layer Protocol [T1095]
  • Web Service: Dead Drop Resolver [T1102.001]
  • Web Service: Bidirectional Communication [T1102.002]
  • Multi-Stage Channels [T1104]
  • Ingress Tool Transfer [T1105]
  • Data Encoding: Standard Encoding [T1132.001]
  • Remote Access Software [T1219]
  • Dynamic Resolution: Domain Generation Algorithms [T1568.002]
  • Non-Standard Port [T1571]
  • Protocol Tunneling [T1572]
  • Encrypted Channel: Symmetric Cryptography [T1573.001]
  • Encrypted Channel: Asymmetric Cryptography [T1573.002]
•  Exfiltration [TA0010]
  • Exfiltration Over C2 Channel [T1041]
  • Exfiltration Over Alternative Protocol: Exfiltration Over Unencrypted/Obfuscated Non-C2 Protocol [T1048.003]
• Impact [TA0040]
  • Data Encrypted for Impact [T1486]
  • Resource Hijacking [T1496]
  • System Shutdown/Reboot [T1529]
  • Disk Wipe: Disk Structure Wipe [T1561.002]

Mitigations

CISA and FBI recommend think tank organizations apply the following critical practices to strengthen their security posture.

Leaders

• Implement a training program to familiarize users with identifying social engineering techniques and phishing emails.

Users/Staff

• Log off remote connections when not in use.
• Be vigilant against tailored spearphishing attacks targeting corporate and personal accounts (including both email and social media accounts).
• Use different passwords for corporate and personal accounts.
• Install antivirus software on personal devices to automatically scan and quarantine suspicious files.
• Employ strong multi-factor authentication for personal accounts, if available.
• Exercise caution when:
  • Opening email attachments, even if the attachment is expected and the sender appears to be known. See Using Caution with Email Attachments.
  • Using removable media (e.g., USB thumb drives, external drives, CDs).

IT Staff/Cybersecurity Personnel

• Segment and segregate networks and functions.
• Change the default username and password of applications and appliances.
• Employ strong multi-factor authentication for corporate accounts.
• Deploy antivirus software on organizational devices to automatically scan and quarantine suspicious files.
• Apply encryption to data at rest and data in transit.
• Use email security appliances to scan and remove malicious email attachments or links.
• Monitor key internal security tools and identify anomalous behavior. Flag any known indicators of compromise or threat actor behaviors for immediate response.
• Organizations can implement mitigations of varying complexity and restrictiveness to reduce the risk posed by threat actors who use Tor (The Onion Router) to carry out malicious activities. See the CISA-FBI Joint Cybersecurity Advisory on Defending Against Malicious Cyber Activity Originating from Tor for mitigation options and additional information.
• Prevent exploitation of known software vulnerabilities by routinely applying software patches and upgrades. Foreign cyber threat actors continue to exploit publicly known—and often dated—software vulnerabilities against broad target sets, including public and private sector organizations. If these vulnerabilities are left unpatched, exploitation often requires few resources and provides threat actors with easy access to victim networks. Review CISA and FBI’s Top 10 Routinely Exploited Vulnerabilities and other CISA alerts that identify vulnerabilities exploited by foreign attackers.
• Implement an antivirus program and a formalized patch management process.
• Block certain websites and email attachments commonly associated with malware (e.g., .scr, .pif, .cpl, .dll, .exe).
• Block email attachments that cannot be scanned by antivirus software (e.g., .zip files).
• Implement Group Policy Object and firewall rules.
• Implement filters at the email gateway and block suspicious IP addresses at the firewall.
• Routinely audit domain and local accounts as well as their permission levels to look for situations that could allow an adversary to gain wide access by obtaining credentials of a privileged account.
• Follow best practices for design and administration of the network to limit privileged account use across administrative tiers.
• Implement a Domain-Based Message Authentication, Reporting & Conformance (DMARC) validation system.
• Disable or block unnecessary remote services.
• Limit access to remote services through centrally managed concentrators.
• Deny direct remote access to internal systems or resources by using network proxies, gateways, and firewalls.
• Limit unnecessary lateral communications.
• Disable file and printer sharing services. If these services are required, use strong passwords or Active Directory authentication.
• Ensure applications do not store sensitive data or credentials insecurely.
• Enable a firewall on agency workstations, configured to deny unsolicited connection requests.
• Disable unnecessary services on agency workstations and servers.
• Scan for and remove suspicious email attachments; ensure any scanned attachment is its "true file type" (i.e., the extension matches the file header).
• Monitor users' web browsing habits; restrict access to suspicious or risky sites. Contact law enforcement or CISA immediately regarding any unauthorized network access identified.
• Visit the MITRE ATT&CK techniques and tactics pages linked in the ATT&CK Profile section above for additional mitigation and detection strategies for this malicious activity targeting think tanks.

Contact Information

Recipients of this report are encouraged to contribute any additional information that they may have related to this threat. To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at www.fbi.gov/contact-us/field, or the FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by email at CyWatch@fbi.gov. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact. To request incident response resources or technical assistance related to these threats, contact CISA at Central@cisa.gov.

References

• CISA Alert: Microsoft Office 365 Security Recommendations
• CISA Alert: Technical Approaches to Uncovering and Remediating Malicious Activity
• CISA Webpage: Telework Guidance
• CISA Webpage: VPN-Related Guidance
• FBI Private Industry Notification: PIN 20200409-001

References

• [1] CyberScoop: As Europe prepares to vote, Microsoft warns of Fancy Bear attacks on democratic think tanks

Revisions

• Initial Version: December 1, 2020

AA20-304A: Iranian Advanced Persistent Threat Actor Identified Obtaining Voter Registration Data
Original release date: October 30, 2020 | Last revised: November 3, 2020

Summary

This advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) version 8 framework. See the ATT&CK for Enterprise version 8 for all referenced threat actor techniques.

This joint cybersecurity advisory was coauthored by the Cybersecurity and Infrastructure Security Agency (CISA) and the Federal Bureau of Investigation (FBI). CISA and the FBI are aware of an Iranian advanced persistent threat (APT) actor targeting U.S. state websites—to include election websites. CISA and the FBI assess this actor is responsible for the mass dissemination of voter intimidation emails to U.S. citizens and the dissemination of U.S. election-related disinformation in mid-October 2020. This disinformation (hereinafter, “the propaganda video”) was in the form of a video purporting to misattribute the activity to a U.S. domestic actor and implies that individuals could cast fraudulent ballots, even from overseas. https://www.odni.gov/index.php/newsroom/press-releases/item/2162-dni-john-ratcliffe-s-remarks-at-press-conference-on-election-security.  (Reference FBI FLASH message ME-000138-TT, disseminated October 29, 2020). Further evaluation by CISA and the FBI has identified the targeting of U.S. state election websites was an intentional effort to influence and interfere with the 2020 U.S. presidential election.

Click here for a PDF version of this report.

Technical Details

Analysis by CISA and the FBI indicates this actor scanned state websites, to include state election websites, between September 20 and September 28, 2020, with the Acunetix vulnerability scanner (Active Scanning: Vulnerability Scanning [T1595.002]). Acunetix is a widely used and legitimate web scanner, which has been used by threat actors for nefarious purposes. Organizations that do not regularly use Acunetix should monitor their logs for any activity from the program that originates from IP addresses provided in this advisory and consider it malicious reconnaissance behavior. 

Additionally, CISA and the FBI observed this actor attempting to exploit websites to obtain copies of voter registration data between September 29 and October 17, 2020 (Exploit Public-Facing Application [T1190]). This includes attempted exploitation of known vulnerabilities, directory traversal, Structured Query Language (SQL) injection, web shell uploads, and leveraging unique flaws in websites. 

CISA and the FBI can confirm that the actor successfully obtained voter registration data in at least one state. The access of voter registration data appeared to involve the abuse of website misconfigurations and a scripted process using the cURL tool to iterate through voter records. A review of the records that were copied and obtained reveals the information was used in the propaganda video. 

CISA and FBI analysis of identified activity against state websites, including state election websites, referenced in this product cannot all be fully attributed to this Iranian APT actor. FBI analysis of the Iranian APT actor’s activity has identified targeting of U.S. elections’ infrastructure (Compromise Infrastructure [T1584]) within a similar timeframe, use of IP addresses and IP ranges—including numerous virtual private network (VPN) service exit nodes—which correlate to this Iran APT actor (Gather Victim Host Information [T1592)]), and other investigative information. 

Reconnaissance

The FBI has information indicating this Iran-based actor attempted to access PDF documents from state voter sites using advanced open-source queries (Search Open Websites and Domains [T1593]). The actor demonstrated interest in PDFs hosted on URLs with the words “vote” or “voter” and “registration.” The FBI identified queries of URLs for election-related sites. 

The FBI also has information indicating the actor researched  the following information in a suspected attempt to further their efforts to survey and exploit state election websites.

• YOURLS exploit
• Bypassing ModSecurity Web Application Firewall
• Detecting Web Application Firewalls
• SQLmap tool

Acunetix Scanning

CISA’s analysis identified the scanning of multiple entities by the Acunetix Web Vulnerability scanning platform between September 20 and September 28, 2020 (Active Scanning: Vulnerability Scanning [T1595.002]). 

The actor used the scanner to attempt SQL injection into various fields in /registration/registration/details with status codes 404 or 500.

/registration/registration/details?addresscity=-1 or 3*2<(0+5+513-513) -- &addressstreet1=xxxxx&btnbeginregistration=begin voter registration&btnnextelectionworkerinfo=next&btnnextpersonalinfo=next&btnnextresdetails=next&btnnextvoterinformation=next&btnsubmit=submit&chkageverno=on&chkageveryes=on&chkcitizenno=on&chkcitizenyes=on&chkdisabledvoter=on&chkelectionworker=on&chkresprivate=1&chkstatecancel=on&dlnumber=1&dob=xxxx/x/x&email=sample@email.tst&firstname=xxxxx&gender=radio&hdnaddresscity=&hdngender=&last4ssn=xxxxx&lastname=xxxxxinjjeuee&mailaddresscountry=sample@xxx.xxx&mailaddressline1=sample@email.tst&mailaddressline2=sample@xxx.xxx&mailaddressline3=sample@xxx.xxx&mailaddressstate=aa&mailaddresszip=sample@xxxx.xxx&mailaddresszipex=sample@xxx.xxx&middlename=xxxxx&overseas=1&partycode=a&phoneno1=xxx-xxx-xxxx&phoneno2=xxx-xxx-xxxx&radio=consent&statecancelcity=xxxxxxx&statecancelcountry=usa&statecancelstate=XXaa&statecancelzip=xxxxx&statecancelzipext=xxxxx&suffixname=esq&txtmailaddresscity=sample@xxx.xxx

Requests

The actor used the following requests associated with this scanning activity.

2020-09-26 13:12:56 x.x.x.x GET /x/x v[$acunetix]=1 443 - x.x.x.x Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.21+(KHTML,+like+Gecko)+Chrome/41.0.2228.0+Safari/537.21 - 200 0 0 0

2020-09-26 13:13:19 X.X.x.x GET /x/x voterid[$acunetix]=1 443 - x.x.x.x Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.21+(KHTML,+like+Gecko)+Chrome/41.0.2228.0+Safari/537.21 - 200 0 0 1375

2020-09-26 13:13:18 .X.x.x GET /x/x voterid=;print(md5(acunetix_wvs_security_test)); 443 - X.X.x.x 

User Agents Observed

CISA and FBI have observed the following user agents associated with this scanning activity.

Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.21+(KHTML,+like+Gecko)+Chrome/41.0.2228.0+Safari/537.21 - 500 0 0 0 

Mozilla/5.0+(X11;+U;+Linux+x86_64;+en-US;+rv:1.9b4)+Gecko/2008031318+Firefox/3.0b4 

Mozilla/5.0+(X11;+U;+Linux+i686;+en-US;+rv:1.8.1.17)+Gecko/20080922+Ubuntu/7.10+(gutsy)+Firefox/2.0.0.17

Exfiltration

Obtaining Voter Registration Data

Following the review of web server access logs, CISA analysts, in coordination with the FBI, found instances of the cURL and FDM User Agents sending GET requests to a web resource associated with voter registration data. The activity occurred between September 29 and October 17, 2020. Suspected scripted activity submitted several hundred thousand queries iterating through voter identification values, and retrieving results with varying levels of success [Gather Victim Identity Information (T1589)]. A sample of the records identified by the FBI reveals they match information in the aforementioned propaganda video.
Requests

The actor used the following requests.

2020-10-17 13:07:51 x.x.x.x GET /x/x voterid=XXXX1 443 - x.x.x.x curl/7.55.1 - 200 0 0 1406

2020-10-17 13:07:55 x.x.x.x GET /x/x voterid=XXXX2 443 - x.x.x.x curl/7.55.1 - 200 0 0 1390

2020-10-17 13:07:58 x.x.x.x GET /x/x voterid=XXXX3 443 - x.x.x.x curl/7.55.1 - 200 0 0 1625

2020-10-17 13:08:00 x.x.x.x GET /x/x voterid=XXXX4 443 - x.x.x.x curl/7.55.1 - 200 0 0 1390

Note: incrementing voterid values in cs_uri_query field

User Agents

CISA and FBI have observed the following user agents.

FDM+3.x

curl/7.55.1

Mozilla/5.0+(Windows+NT+6.1;+WOW64)+AppleWebKit/537.21+(KHTML,+like+Gecko)+Chrome/41.0.2228.0+Safari/537.21 - 500 0 0 0 
Mozilla/5.0+(X11;+U;+Linux+x86_64;+en-US;+rv:1.9b4)+Gecko/2008031318+Firefox/3.0b4

See figure 1 below for a timeline of the actor’s malicious activity.

Figure 1: Overview of malicious activity

Mitigations

Detection

Acunetix Scanning

Organizations can identify Acunetix scanning activity by using the following keywords while performing log analysis.

• $acunetix
• acunetix_wvs_security_test

Indicators of Compromise

For a downloadable copy of IOCs, see AA20-304A.stix.

Disclaimer: many of the IP addresses included below likely correspond to publicly available VPN services, which can be used by individuals all over the world. This creates the potential for a significant number of false positives; only activity listed in this advisory warrants further investigation. The actor likely uses various IP addresses and VPN services.

The following IPs have been associated with this activity.

• 102.129.239[.]185 (Acunetix Scanning)
• 143.244.38[.]60 (Acunetix Scanning and cURL requests)
• 45.139.49[.]228 (Acunetix Scanning)
• 156.146.54[.]90 (Acunetix Scanning)
• 109.202.111[.]236 (cURL requests)
• 185.77.248[.]17 (cURL requests)
• 217.138.211[.]249 (cURL requests)
• 217.146.82[.]207 (cURL requests)
• 37.235.103[.]85 (cURL requests)
• 37.235.98[.]64 (cURL requests)
• 70.32.5[.]96 (cURL requests)
• 70.32.6[.]20 (cURL requests)
• 70.32.6[.]8 (cURL requests)
• 70.32.6[.]97 (cURL requests)
• 70.32.6[.]98 (cURL requests)
• 77.243.191[.]21 (cURL requests and FDM+3.x [Free Download Manager v3] enumeration/iteration)
• 92.223.89[.]73 (cURL requests)

CISA and the FBI are aware the following IOCs have been used by this Iran-based actor. These IP addresses facilitated the mass dissemination of voter intimidation email messages on October 20, 2020.

• 195.181.170[.]244 (Observed September 30 and October 20, 2020)
• 102.129.239[.]185 (Observed September 30, 2020)
• 104.206.13[.]27 (Observed September 30, 2020)
• 154.16.93[.]125 (Observed September 30, 2020)
• 185.191.207[.]169 (Observed September 30, 2020)
• 185.191.207[.]52 (Observed September 30, 2020)
• 194.127.172[.]98 (Observed September 30, 2020)
• 194.35.233[.]83 (Observed September 30, 2020)
• 198.147.23[.]147 (Observed September 30, 2020)
• 198.16.66[.]139(Observed September 30, 2020)
• 212.102.45[.]3 (Observed September 30, 2020)
• 212.102.45[.]58 (Observed September 30, 2020)
• 31.168.98[.]73 (Observed September 30, 2020)
• 37.120.204[.]156 (Observed September 30, 2020)
• 5.160.253[.]50 (Observed September 30, 2020)
• 5.253.204[.]74 (Observed September 30, 2020)
• 64.44.81[.]68 (Observed September 30, 2020)
• 84.17.45[.]218 (Observed September 30, 2020)
• 89.187.182[.]106 (Observed September 30, 2020)
• 89.187.182[.]111 (Observed September 30, 2020)
• 89.34.98[.]114 (Observed September 30, 2020)
• 89.44.201[.]211 (Observed September 30, 2020)

Recommendations

The following list provides recommended self-protection mitigation strategies against cyber techniques used by advanced persistent threat actors: 

• Validate input as a method of sanitizing untrusted input submitted by web application users. Validating input can significantly reduce the probability of successful exploitation by providing protection against security flaws in web applications. The types of attacks possibly prevented include SQL injection, Cross Site Scripting (XSS), and command injection.
• Audit your network for systems using Remote Desktop Protocol (RDP) and other internet-facing services. Disable unnecessary services and install available patches for the services in use. Users may need to work with their technology vendors to confirm that patches will not affect system processes.
• Verify all cloud-based virtual machine instances with a public IP, and avoid using open RDP ports, unless there is a valid need. Place any system with an open RDP port behind a firewall and require users to use a VPN to access it through the firewall.
• Enable strong password requirements and account lockout policies to defend against brute-force attacks.
• Apply multi-factor authentication, when possible.
• Maintain a good information back-up strategy by routinely backing up all critical data and system configuration information on a separate device. Store the backups offline, verify their integrity, and verify the restoration process.
• Enable logging and ensure logging mechanisms capture RDP logins. Keep logs for a minimum of 90 days and review them regularly to detect intrusion attempts.
• When creating cloud-based virtual machines, adhere to the cloud provider's best practices for remote access.
• Ensure third parties that require RDP access follow internal remote access policies.
• Minimize network exposure for all control system devices. Where possible, critical devices should not have RDP enabled.
• Regulate and limit external to internal RDP connections. When external access to internal resources is required, use secure methods, such as a VPNs. However, recognize the security of VPNs matches the security of the connected devices.
• Use security features provided by social media platforms; use strong passwords, change passwords frequently, and use a different password for each social media account. 
• See CISA’s Tip on Best Practices for Securing Election Systems for more information. 

General Mitigations

Keep applications and systems updated and patched

Apply all available software updates and patches and automate this process to the greatest extent possible (e.g., by using an update service provided directly from the vendor). Automating updates and patches is critical because of the speed of threat actors to create new exploits following the release of  a patch. These “N-day” exploits can be as damaging as zero-day exploits. Ensure the authenticity and integrity of vendor updates by using signed updates delivered over protected links. Without the rapid and thorough application of patches, threat actors can operate inside a defender’s patch cycle. NSA "NSA'S Top Ten Cybersecurity Mitigation Strategies" https://www.nsa.gov/Portals/70/documents/what-we-do/cybersecurity/professional-resources/csi-nsas-top10-cybersecurity-mitigation-strategies.pdf Additionally, use tools (e.g., the OWASP Dependency-Check Project tool https://owasp.org/www-project-dependency-check/) to identify the publicly known vulnerabilities in third-party libraries depended upon by the application.

Scan web applications for SQL injection and other common web vulnerabilities

Implement a plan to scan public-facing web servers for common web vulnerabilities (e.g., SQL injection, cross-site scripting) by using a commercial web application vulnerability scanner in combination with a source code scanner. https://apps.nsa.gov/iaarchive/library/ia-guidance/tech-briefs/defending-against-the-exploitation-of-sql-vulnerabilities-to.cfm Fixing or patching vulnerabilities after they are identified is especially crucial for networks hosting older web applications. As sites get older, more vulnerabilities are discovered and exposed.

Deploy a web application firewall  

Deploy a web application firewall (WAF) to prevent invalid input attacks and other attacks destined for the web application. WAFs are intrusion/detection/prevention devices that inspect each web request made to and from the web application to determine if the request is malicious. Some WAFs install on the host system and others are dedicated devices that sit in front of the web application. WAFs also weaken the effectiveness of automated web vulnerability scanning tools. 

Deploy techniques to protect against web shells

Patch web application vulnerabilities or fix configuration weaknesses that allow web shell attacks, and follow guidance on detecting and preventing web shell malware. NSA & ASD "CyberSecurity Information: Detect and Prevent Web Shell Malware" https://media.defense.gov/2020/Jun/09/2002313081/-1/-1/0/CSI-DETECT-AND-PREVENT-WEB-SHELL-MALWARE-20200422.PDF Malicious cyber actors often deploy web shells—software that can enable remote administration—on a victim’s web server. Malicious cyber actors can use web shells to execute arbitrary system commands commonly sent over HTTP or HTTPS. Attackers often create web shells by adding or modifying a file in an existing web application. Web shells provide attackers with persistent access to a compromised network using communications channels disguised to blend in with legitimate traffic. Web shell malware is a long-standing, pervasive threat that continues to evade many security tools. 

Use multi-factor authentication for administrator accounts

Prioritize protection for accounts with elevated privileges, remote access, or used on high-value assets. https://us-cert.cisa.gov/cdm/event/Identifying-and-Protecting-High-Value-Assets-Closer-Look-Governance-Needs-HVAs Use physical token-based authentication systems to supplement knowledge-based factors such as passwords and personal identification numbers (PINs). NSA "NSA'S Top Ten Cybersecurity Mitigation Strategies" https://www.nsa.gov/Portals/70/documents/what-we-do/cybersecurity/professional-resources/csi-nsas-top10-cybersecurity-mitigation-strategies.pdf Organizations should migrate away from single-factor authentication, such as password-based systems, which are subject to poor user choices and more susceptible to credential theft, forgery, and password reuse across multiple systems.

Remediate critical web application security risks

First, identify and remediate critical web application security risks. Next, move on to other less critical vulnerabilities. Follow available guidance on securing web applications. NSA “Building Web Applications – Security for Developers” https://apps.nsa.gov/iaarchive/library/ia-guidance/security-tips/building-web-applications-security-recommendations-for.cfm https://owasp.org/www-project-top-ten/ https://cwe.mitre.org/top25/archive/2020/2020_cwe_top25.html

How do I respond to unauthorized access to election-related systems?

Implement your security incident response and business continuity plan

It may take time for your organization’s IT professionals to isolate and remove threats to your systems and restore normal operations. In the meantime, take steps to maintain your organization’s essential functions according to your business continuity plan. Organizations should maintain and regularly test backup plans, disaster recovery plans, and business continuity procedures.

Contact CISA or law enforcement immediately 

To report an intrusion and to request incident response resources or technical assistance, contact CISA (Central@cisa.gov or 888-282-0870) or the FBI through a local field office or the FBI’s Cyber Division (CyWatch@ic.fbi.gov or 855-292-3937).

Resources

• CISA Tip: Best Practices for Securing Election Systems
• CISA Tip: Securing Voter Registration Data 
• CISA Tip: Website Security 
• CISA Tip: Avoiding Social Engineering and Phishing Attacks
• CISA Tip: Securing Network Infrastructure Devices 
• Joint Advisory: Technical Approaches to Uncovering and Remediating Malicious Activity
• CISA Insights: Actions to Counter Email-Based Attacks on Election-related Entities 
• FBI and CISA Public Service Announcement (PSA): Spoofed Internet Domains and Email Accounts Pose Cyber and Disinformation Risks to Voters
• FBI and CISA PSA: Foreign Actors Likely to Use Online Journals to Spread Disinformation Regarding 2020 Elections 
• FBI and CISA PSA: Distributed Denial of Service Attacks Could Hinder Access to Voting Information, Would Not Prevent Voting 
• FBI and CISA PSA: False Claims of Hacked Voter Information Likely Intended to Cast Doubt on Legitimacy of U.S. Elections
• FBI and CISA PSA: Cyber Threats to Voting Processes Could Slow But Not Prevent Voting 
• FBI and CISA PSA: Foreign Actors and Cybercriminals Likely to Spread Disinformation Regarding 2020 Election Result

Revisions

• October 30, 2020: Initial Version
• November 3, 2020: Updated IOC disclaimer to emphasize that only activity listed in this alert warrants further investigation.

AA20-302A: Ransomware Activity Targeting the Healthcare and Public Health Sector
Original release date: October 28, 2020 | Last revised: November 2, 2020

Summary

This advisory was updated to include information on Conti, TrickBot, and BazarLoader, including new IOCs and Yara Rules for detection.

This advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) version 7 framework. See the ATT&CK for Enterprise version 7 for all referenced threat actor tactics and techniques.

This joint cybersecurity advisory was coauthored by the Cybersecurity and Infrastructure Security Agency (CISA), the Federal Bureau of Investigation (FBI), and the Department of Health and Human Services (HHS). This advisory describes the tactics, techniques, and procedures (TTPs) used by cybercriminals against targets in the Healthcare and Public Health (HPH) Sector to infect systems with ransomware, notably Ryuk and Conti, for financial gain.

CISA, FBI, and HHS have credible information of an increased and imminent cybercrime threat to U.S. hospitals and healthcare providers. CISA, FBI, and HHS are sharing this information to provide warning to healthcare providers to ensure that they take timely and reasonable precautions to protect their networks from these threats.

Click here for a PDF version of this report.

Key Findings

• CISA, FBI, and HHS assess malicious cyber actors are targeting the HPH Sector with TrickBot and BazarLoader malware, often leading to ransomware attacks, data theft, and the disruption of healthcare services.
• These issues will be particularly challenging for organizations within the COVID-19 pandemic; therefore, administrators will need to balance this risk when determining their cybersecurity investments.

Technical Details

Threat Details

The cybercriminal enterprise behind TrickBot, which is likely also the creator of BazarLoader malware, has continued to develop new functionality and tools, increasing the ease, speed, and profitability of victimization. These threat actors increasingly use loaders—like TrickBot and BazarLoader (or BazarBackdoor)—as part of their malicious cyber campaigns. Cybercriminals disseminate TrickBot and BazarLoader via phishing campaigns that contain either links to malicious websites that host the malware or attachments with the malware. Loaders start the infection chain by distributing the payload; they deploy and execute the backdoor from the command and control (C2) server and install it on the victim’s machine.

TrickBot

What began as a banking trojan and descendant of Dyre malware, TrickBot now provides its operators a full suite of tools to conduct a myriad of illegal cyber activities. These activities include credential harvesting, mail exfiltration, cryptomining, point-of-sale data exfiltration, and the deployment of ransomware, such as Ryuk and Conti.

In early 2019, the FBI began to observe new TrickBot modules named Anchor, which cyber actors typically used in attacks targeting high-profile victims—such as large corporations. These attacks often involved data exfiltration from networks and point-of-sale devices. As part of the new Anchor toolset, TrickBot developers created anchor_dns, a tool for sending and receiving data from victim machines using Domain Name System (DNS) tunneling.

anchor_dns is a backdoor that allows victim machines to communicate with C2 servers over DNS to evade typical network defense products and make their malicious communications blend in with legitimate DNS traffic. anchor_dns uses a single-byte XOR cipher to encrypt its communications, which have been observed using key 0xB9. Once decrypted, the string anchor_dns can be found in the DNS request traffic.

TrickBot Indicators of Compromise

After successful execution of the malware, TrickBot copies itself as an executable file with a 12-character randomly generated file name (e.g. mfjdieks.exe) and places this file in one of the following directories.

• C:\Windows\
• C:\Windows\SysWOW64\
• C:\Users\[Username]\AppData\Roaming\

Once the executable is running and successful in establishing communication with C2s, the executable places appropriate modules downloaded from C2s for the infected processor architecture type (32 or 64 bit instruction set), to the infected host’s %APPDATA% or %PROGRAMDATA% directory, such as %AppData\Roaming\winapp. Some commonly named plugins that are created in a Modules subdirectory are (the detected architecture is appended to the module filename, e.g., importDll32 or importDll64):

• Systeminfo
• importDll
• outlookDll
• injectDll with a directory (ex. injectDLL64_configs) containing configuration files:
  • dinj
  • sinj
  • dpost
• mailsearcher with a directory (ex. mailsearcher64_configs) containing configuration file:
  • mailconf
• networkDll with a directory (ex. networkDll64_configs) containing configuration file:
  • dpost
• wormDll
• tabDll
• shareDll

Filename client_id or data or FAQ with the assigned bot ID of the compromised system is created in the malware directory. Filename group_tag or Readme.md containing the TrickBot campaign IDs is created in the malware directory.

The malware may also drop a file named anchorDiag.txt in one of the directories listed above.

Part of the initial network communications with the C2 server involves sending information about the victim machine such as its computer name/hostname, operating system version, and build via a base64-encoded GUID. The GUID is composed of /GroupID/ClientID/ with the following naming convention:

/anchor_dns/[COMPUTERNAME]_[WindowsVersionBuildNo].[32CharacterString]/.

The malware uses scheduled tasks that run every 15 minutes to ensure persistence on the victim machine. The scheduled task typically uses the following naming convention.

[random_folder_name_in_%APPDATA%_excluding_Microsoft]

autoupdate#[5_random_numbers] (e.g., Task autoupdate#16876).

After successful execution, anchor_dns further deploys malicious batch scripts (.bat) using PowerShell commands.

The malware deploys self-deletion techniques by executing the following commands.

• cmd.exe /c timeout 3 && del C:\Users\[username]\[malware_sample]
• cmd.exe /C PowerShell \"Start-Sleep 3; Remove-Item C:\Users\[username]\[malware_sample_location]\"

The following domains found in outbound DNS records are associated with anchor_dns.

• kostunivo[.]com
• chishir[.]com
• mangoclone[.]com
• onixcellent[.]com

This malware used the following legitimate domains to test internet connectivity.

• ipecho[.]net
• api[.]ipify[.]org
• checkip[.]amazonaws[.]com
• ip[.]anysrc[.]net
• wtfismyip[.]com
• ipinfo[.]io
• icanhazip[.]com
• myexternalip[.]com
• ident[.]me

Currently, there is an open-source tracker for TrickBot C2 servers located at https://feodotracker.abuse.ch/browse/trickbot/.

The anchor_dns malware historically used the following C2 servers.

• 23[.]95[.]97[.]59
• 51[.]254[.]25[.]115
• 193[.]183[.]98[.]66
• 91[.]217[.]137[.]37
• 87[.]98[.]175[.]85

TrickBot YARA Rules

BazarLoader/BazarBackdoor

Beginning in approximately early 2020, actors believed to be associated with TrickBot began using BazarLoader and BazarBackdoor to infect victim networks. The loader and backdoor work closely together to achieve infection and communicate with the same C2 infrastructure. Campaigns using Bazar represent a new technique for cybercriminals to infect and monetize networks and have increasingly led to the deployment of ransomware, including Ryuk. BazarLoader has become one of the most commonly used vectors for ransomware deployment.

Deployment of the BazarLoader malware typically comes from phishing email and contains the following:

• Phishing emails are typically delivered by commercial mass email delivery services. Email received by a victim will contain a link to an actor-controlled Google Drive document or other free online filehosting solutions, typically purporting to be a PDF file.
• This document usually references a failure to create a preview of the document and contains a link to a URL hosting a malware payload in the form of a misnamed or multiple extension file.
• Emails can appear as routine, legitimate business correspondence about customer complaints, hiring decision, or other important tasks that require the attention of the recipient.  
• Some email communications have included the recipient’s name or employer name in the subject line and/or email body.

Through phishing emails linking users to Google Documents, actors used the below identified file names to install BazarLoader:

• Report-Review26-10.exe
• Review_Report15-10.exe
• Document_Print.exe
• Report10-13.exe
• Text_Report.exe

Bazar activity can be identified by searching the system startup folders and Userinit values under the HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon registry key:

%APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup\adobe.lnk

For a comprehensive list of indicators of compromise regarding the BazarLocker and other malware, see https://www.fireeye.com/blog/threat-research/2020/10/kegtap-and-singlemalt-with-a-ransomware-chaser.html.

Indicators

In addition to TrickBot and BazarLoader, threat actors are using malware, such as KEGTAP, BEERBOT, SINGLEMALT, and others as they continue to change tactics, techniques, and procedures in their highly dynamic campaign. The following C2 servers are known to be associated with this malicious activity.

• 45[.]148[.]10[.]92
• 170[.]238[.]117[.]187
• 177[.]74[.]232[.]124
• 185[.]68[.]93[.]17
• 203[.]176[.]135[.]102
• 96[.]9[.]73[.]73
• 96[.]9[.]77[.]142
• 37[.]187[.]3[.]176
• 45[.]89[.]127[.]92
• 62[.]108[.]35[.]103
• 91[.]200[.]103[.]242
• 103[.]84[.]238[.]3
• 36[.]89[.]106[.]69
• 103[.]76[.]169[.]213
• 36[.]91[.]87[.]227
• 105[.]163[.]17[.]83
• 185[.]117[.]73[.]163
• 5[.]2[.]78[.]118
• 185[.]90[.]61[.]69
• 185[.]90[.]61[.]62
• 86[.]104[.]194[.]30
• 31[.]131[.]21[.]184
• 46[.]28[.]64[.]8
• 104[.]161[.]32[.]111
• 107[.]172[.]140[.]171
• 131[.]153[.]22[.]148
• 195[.]123[.]240[.]219
• 195[.]123[.]242[.]119
• 195[.]123[.]242[.]120
• 51[.]81[.]113[.]25
• 74[.]222[.]14[.]27

Ryuk Ransomware

Typically Ryuk has been deployed as a payload from banking Trojans such as TrickBot. (See the United Kingdom (UK) National Cyber Security Centre (NCSC) advisory, Ryuk Ransomware Targeting Organisations Globally, on their ongoing investigation into global Ryuk ransomware campaigns and associated Emotet and TrickBot malware.) Ryuk first appeared in August 2018 as a derivative of Hermes 2.1 ransomware, which first emerged in late 2017 and was available for sale on the open market as of August 2018. Ryuk still retains some aspects of the Hermes code. For example, all of the files encrypted by Ryuk contain the HERMES tag but, in some infections, the files have .ryk added to the filename, while others do not. In other parts of the ransomware code, Ryuk has removed or replaced features of Hermes, such as the restriction against targeting specific Eurasia-based systems.

While negotiating the victim network, Ryuk actors will commonly use commercial off-the-shelf products—such as Cobalt Strike and PowerShell Empire—in order to steal credentials. Both frameworks are very robust and are highly effective dual-purpose tools, allowing actors to dump clear text passwords or hash values from memory with the use of Mimikatz. This allows the actors to inject malicious dynamic-link library into memory with read, write, and execute permissions. In order to maintain persistence in the victim environment, Ryuk actors have been known to use scheduled tasks and service creation.

Ryuk actors will quickly map the network in order to enumerate the environment to understand the scope of the infection. In order to limit suspicious activity and possible detection, the actors choose to live off the land and, if possible, use native tools—such as net view, net computers, and ping—to locate mapped network shares, domain controllers, and active directory. In order to move laterally throughout the network, the group relies on native tools, such as PowerShell, Windows Management Instrumentation (WMI), Windows Remote Management , and Remote Desktop Protocol (RDP). The group also uses third-party tools, such as Bloodhound.

Once dropped, Ryuk uses AES-256 to encrypt files and an RSA public key to encrypt the AES key. The Ryuk dropper drops a .bat file that attempts to delete all backup files and Volume Shadow Copies (automatic backup snapshots made by Windows), preventing the victim from recovering encrypted files without the decryption program.

In addition, the attackers will attempt to shut down or uninstall security applications on the victim systems that might prevent the ransomware from executing. Normally this is done via a script, but if that fails, the attackers are capable of manually removing the applications that could stop the attack. The RyukReadMe file placed on the system after encryption provides either one or two email  addresses, using the end-to-end encrypted email provider Protonmail, through which the victim can contact the attacker(s). While earlier versions provide a ransom amount in the initial notifications, Ryuk users are now designating a ransom amount only after the victim makes contact.

The victim is told how much to pay to a specified Bitcoin wallet for the decryptor and is provided a sample decryption of two files.

Initial testing indicates that the RyukReadMe file does not need to be present for the decryption script to run successfully but other reporting advises some files will not decrypt properly without it. Even if run correctly, there is no guarantee the decryptor will be effective. This is further complicated because the RyukReadMe file is deleted when the script is finished. This may affect the decryption script unless it is saved and stored in a different location before running.

According to MITRE, Ryuk uses the ATT&CK techniques listed in table 1.

Table 1: Ryuk ATT&CK techniques

Mitigations

For a downloadable copy of IOCs, see AA20-302A.stix. For additional IOCs detailing this activity, see https://gist.github.com/aaronst/6aa7f61246f53a8dd4befea86e832456.

Plans and Policies

CISA, FBI, and HHS encourage HPH Sector organizations to maintain business continuity plans—the practice of executing essential functions through emergencies (e.g., cyberattacks)—to minimize service interruptions. Without planning, provision, and implementation of continuity principles, organizations may be unable to continue operations. Evaluating continuity and capability will help identify continuity gaps. Through identifying and addressing these gaps, organizations can establish a viable continuity program that will help keep them functioning during cyberattacks or other emergencies. CISA, FBI, and HHS suggest HPH Sector organizations review or establish patching plans, security policies, user agreements, and business continuity plans to ensure they address current threats posed by malicious cyber actors.

Network Best Practices

• Patch operating systems, software, and firmware as soon as manufacturers release updates.
• Check configurations for every operating system version for HPH organization-owned assets to prevent issues from arising that local users are unable to fix due to having local administration disabled.
• Regularly change passwords to network systems and accounts and avoid reusing passwords for different accounts.
• Use multi-factor authentication where possible.
• Disable unused remote access/Remote Desktop Protocol (RDP) ports and monitor remote access/RDP logs.
• Implement application and remote access allow listing to only allow systems to execute programs known and permitted by the established security policy.
• Audit user accounts with administrative privileges and configure access controls with least privilege in mind.
• Audit logs to ensure new accounts are legitimate.
• Scan for open or listening ports and mediate those that are not needed.
• Identify critical assets such as patient database servers, medical records, and teleheatlh and telework infrastructure; create backups of these systems and house the backups offline from the network.
• Implement network segmentation. Sensitive data should not reside on the same server and network segment as the email environment.
• Set antivirus and anti-malware solutions to automatically update; conduct regular scans.

Ransomware Best Practices

CISA, FBI and HHS do not recommend paying ransoms. Payment does not guarantee files will be recovered. It may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. In addition to implementing the above network best practices, the FBI, CISA and HHS also recommend the following:

• Regularly back up data, air gap, and password protect backup copies offline.
• Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, secure location.

User Awareness Best Practices

• Focus on awareness and training. Because end users are targeted, make employees and stakeholders aware of the threats—such as ransomware and phishing scams—and how they are delivered. Additionally, provide users training on information security principles and techniques as well as overall emerging cybersecurity risks and vulnerabilities.
• Ensure that employees know who to contact when they see suspicious activity or when they believe they have been a victim of a cyberattack. This will ensure that the proper established mitigation strategy can be employed quickly and efficiently.

Recommended Mitigation Measures

System administrators who have indicators of a TrickBot network compromise should immediately take steps to back up and secure sensitive or proprietary data. TrickBot infections may be indicators of an imminent ransomware attack; system administrators should take steps to secure network devices accordingly. Upon evidence of a TrickBot infection, review DNS logs and use the XOR key of 0xB9 to decode XOR encoded DNS requests to reveal the presence of Anchor_DNS, and maintain and provide relevant logs.

GENERAL RANSOMWARE MITIGATIONS — HPH SECTOR

This section is based on CISA and Multi-State Information Sharing and Analysis Center (MS-ISAC)'s Joint Ransomware Guide, which can be found at https://www.cisa.gov/publication/ransomware-guide.

CISA, FBI, and HHS recommend that healthcare organizations implement both ransomware prevention and ransomware response measures immediately.

Ransomware Prevention

Join and Engage with Cybersecurity Organizations

CISA, FBI, and HHS recommend that healthcare organizations take the following initial steps:

• Join a healthcare information sharing organization, H-ISAC:
  • Health Information Sharing and Analysis Center (H-ISAC): https://h-isac.org/membership-account/join-h-isac/
  • Sector-based ISACs - National Council of ISACs: https://www.nationalisacs.org/member-isacs
  • Information Sharing and Analysis Organization (ISAO) Standards Organization: https://www.isao.org/information-sharing-groups/
• Engage with CISA and FBI, as well as HHS—through the HHS Health Sector Cybersecurity Coordination Center (HC3)—to build a lasting partnership and collaborate on information sharing, best practices, assessments, and exercises.
  • CISA: cisa.gov, https://us-cert.cisa.gov/mailing-lists-and-feeds, central@cisa.gov  
  • FBI: ic3.gov, www.fbi.gov/contact-us/field, CyWatch@fbi.gov
  • HHS/HC3: http://www.hhs.gov/hc3, HC3@HHS.gov

Engaging with the H-ISAC, ISAO, CISA, FBI, and HHS/HC3 will enable your organization to receive critical information and access to services to better manage the risk posed by ransomware and other cyber threats.

Follow Ransomware Best Practices

Refer to the best practices and references below to help manage the risk posed by ransomware and support your organization’s coordinated and efficient response to a ransomware incident. Apply these practices to the greatest extent possible based on availability of organizational resources.

• It is critical to maintain offline, encrypted backups of data and to regularly test your backups. Backup procedures should be conducted on a regular basis. It is important that backups be maintained offline or in separated networks as many ransomware variants attempt to find and delete any accessible backups. Maintaining offline, current backups is most critical because there is no need to pay a ransom for data that is readily accessible to your organization.
  • Use the 3-2-1 rule as a guideline for backup practices. The rule states that three copies of all critical data are retained on at least two different types of media and at least one of them is stored offline.
  • Maintain regularly updated “gold images” of critical systems in the event they need to be rebuilt. This entails maintaining image “templates” that include a preconfigured operating system (OS) and associated software applications that can be quickly deployed to rebuild a system, such as a virtual machine or server.
  • Retain backup hardware to rebuild systems in the event rebuilding the primary system is not preferred.
    • Hardware that is newer or older than the primary system can present installation or compatibility hurdles when rebuilding from images.
    • Ensure all backup hardware is properly patched.
• In addition to system images, applicable source code or executables should be available (stored with backups, escrowed, license agreement to obtain, etc.). It is more efficient to rebuild from system images, but some images will not install on different hardware or platforms correctly; having separate access to needed software will help in these cases.
• Create, maintain, and exercise a basic cyber incident response plan and associated communications plan that includes response and notification procedures for a ransomware incident.
  • Review available incident response guidance, such as CISA’s Technical Approaches to Uncovering and Remediating Malicious Activity https://us-cert.cisa.gov/ncas/alerts/aa20-245a.
• Help your organization better organize around cyber incident response.
• Develop a cyber incident response plan.
• The Ransomware Response Checklist, available in the CISA and MS-ISAC Joint Ransomware Guide, serves as an adaptable, ransomware- specific annex to organizational cyber incident response or disruption plans.
• Review and implement as applicable MITRE’s Medical Device Cybersecurity: Regional Incident Preparedness and Response Playbook (https://www.mitre.org/sites/default/files/publications/pr-18-1550-Medical-Device-Cybersecurity-Playbook.pdf).
• Develop a risk management plan that maps critical health services and care to the necessary information systems; this will ensure that the incident response plan will contain the proper triage procedures.
• Plan for the possibility of critical information systems being inaccessible for an extended period of time. This should include but not be limited to the following:
  • Print and properly store/protect hard copies of digital information that would be required for critical patient healthcare.
  • Plan for and periodically train staff to handle the re-routing of incoming/existing patients in an expedient manner if information systems were to abruptly and unexpectedly become unavailable.
  • Coordinate the potential for surge support with other healthcare facilities in the greater local area. This should include organizational leadership periodically meeting and collaborating with counterparts in the greater local area to create/update plans for their facilities to both abruptly send and receive a significant amount of critical patients for immediate care. This may include the opportunity to re-route healthcare employees (and possibly some equipment) to provide care along with additional patients.
• Consider the development of a second, air-gapped communications network that can provide a minimum standard of backup support for hospital operations if the primary network becomes unavailable if/when needed.
• Predefine network segments, IT capabilities and other functionality that can either be quickly separated from the greater network or shut down entirely without impacting operations of the rest of the IT infrastructure.
• Legacy devices should be identified and inventoried with highest priority and given special consideration during a ransomware event.
• See CISA and MS-ISAC's Joint Ransomware Guide for infection vectors including internet-facing vulnerabilities and misconfigurations; phishing; precursor malware infection; and third parties and managed service providers.
• HHS/HC3 tracks ransomware that is targeting the HPH Sector; this information can be found at http://www.hhs.gov/hc3.

Hardening Guidance

• The Food and Drug Administration provides multiple guidance documents regarding the hardening of healthcare and specifically medical devices found here: https://www.fda.gov/medical-devices/digital-health-center-excellence/cybersecurity.
• See CISA and MS-ISAC's Joint Ransomware Guide for additional in-depth hardening guidance.

Contact CISA for These No-Cost Resources

• Information sharing with CISA and MS-ISAC (for SLTT organizations) includes bi-directional sharing of best practices and network defense information regarding ransomware trends and variants as well as malware that is a precursor to ransomware.
• Policy-oriented or technical assessments help organizations understand how they can improve their defenses to avoid ransomware infection: https://www.cisa.gov/cyber-resource-hub.
  • Assessments include Vulnerability Scanning and Phishing Campaign Assessment.
• Cyber exercises evaluate or help develop a cyber incident response plan in the context of a ransomware incident scenario.
• CISA Cybersecurity Advisors (CSAs) advise on best practices and connect you with CISA resources to manage cyber risk.
• Contacts:
  • SLTT organizations: CyberLiaison_SLTT@cisa.dhs.gov
  • Private sector organizations: CyberLiaison_Industry@cisa.dhs.gov

Ransomware Quick References

• Ransomware: What It Is and What to Do About It (CISA): General ransomware guidance for organizational leadership and more in-depth information for CISOs and technical staff: https://www.us-cert.cisa.gov/sites/default/files/publications/Ransomware_Executive_One-Pager_and_Technical_ Document-FINAL.pdf
• Ransomware (CISA): Introduction to ransomware, notable links to CISA products on protecting networks, specific ransomware threats, and other resources: https://www.us-cert.cisa.gov/Ransomware  
• HHS/HC3: Ransomware that impacts HPH is tracked by the HC3 and can be found at www.hhs.gov/hc3
• Security Primer – Ransomware (MS-ISAC): Outlines opportunistic and strategic ransomware campaigns, common infection vectors, and best practice recommendations: https://www.cisecurity.org/white-papers/security-primer-ransomware/
• Ransomware: Facts, Threats, and Countermeasures (MS- ISAC): Facts about ransomware, infection vectors, ransomware capabilities, and how to mitigate the risk of ransomware infection: https://www.cisecurity.org/blog/ransomware- facts-threats-and-countermeasures/
• HHS Ransomware Fact Sheet: https://www.hhs.gov/sites/default/files/RansomwareFactSheet.pdf
• NIST Securing Data Integrity White Paper: https://csrc.nist.gov/publications/detail/white-paper/2020/10/01/securing-data-integrity-against-ransomware-attacks/draft

Ransomware Response Checklist

Remember: Paying the ransom will not ensure your data is decrypted or that your systems or data will no longer be compromised. CISA, FBI, and HHS do not recommend paying ransom.

Should your organization be a victim of ransomware, CISA strongly recommends responding by using the Ransomware Response Checklist located in CISA and MS-ISAC's Joint Ransomware Guide, which contains steps for detection and analysis as well as containment and eradication.

Consider the Need For Extended Identification or Analysis

If extended identification or analysis is needed, CISA, HHS/HC3, or federal law enforcement may be interested in any of the following information that your organization determines it can legally share:

• Recovered executable file
• Copies of the readme file – DO NOT REMOVE the file or decryption may not be possible
• Live memory (RAM) capture from systems with additional signs of compromise (use of exploit toolkits, RDP activity, additional files found locally)
• Images of infected systems with additional signs of compromise (use of exploit toolkits, RDP activity, additional files found locally)
• Malware samples
• Names of any other malware identified on your system
• Encrypted file samples
• Log files (Windows Event Logs from compromised systems, Firewall logs, etc.)
• Any PowerShell scripts found having executed on the systems
• Any user accounts created in Active Directory or machines added to the network during the exploitation
• Email addresses used by the attackers and any associated phishing emails
• A copy of the ransom note
• Ransom amount and whether or not the ransom was paid
• Bitcoin wallets used by the attackers
• Bitcoin wallets used to pay the ransom (if applicable)
• Copies of any communications with attackers

Upon voluntary request, CISA can assist with analysis (e.g., phishing emails, storage media, logs, malware) at no cost to support your organization in understanding the root cause of an incident, even in the event additional remote assistance is not requested.

• CISA – Advanced Malware Analysis Center: https://www.malware.us-cert.gov/MalwareSubmission/pages/submission.jsf
• Remote Assistance – Request via Central@cisa.gov

Contact Information

CISA, FBI, and HHS recommend identifying and having on hand the following contact information for ready use should your organization become a victim of a ransomware incident. Consider contacting these organizations for mitigation and response assistance or for purpose of notification.

• State and Local Response Contacts
• IT/IT Security Team – Centralized Cyber Incident Reporting
• State and Local Law Enforcement
• Fusion Center        
• Managed/Security Service Providers
• Cyber Insurance       

To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at www.fbi.gov/contact-us/field, or the FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by email at CyWatch@fbi.gov. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact. To request incident response resources or technical assistance related to these threats, contact CISA at Central@cisa.gov.

Additionally, see CISA and MS-ISAC's Joint Ransomware Guide for information on contacting—and what to expect from contacting—federal asset response and federal threat response contacts.

Disclaimer

This document is marked TLP:WHITE. Disclosure is not limited. Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction. For more information on the Traffic Light Protocol, see https://cisa.gov/tlp.

References

• CISA Emergency Services Sector Continuity Planning Suite
• CISA MS-ISAC Joint Ransomware Guide
• CISA Tip: Avoiding Social Engineering and Phishing Attacks
• FBI PSA: “High-Impact Ransomware Attacks Threaten U.S. Businesses and Organizations"
• Health Industry Cybersecurity Tactical Crisis Response
• Health Industry Cybersecurity Practices (HICP)
• HHS - Ransomware Spotlight Webinar
• HHS - Health Industry Cybersecurity Practices: Managing Threats and Protecting Patients
• HHS - Ransomware Briefing
• HHS - Aggressive Ransomware Impacts
• HHS - Ransomware Fact Sheet
• HHS - Cyber Attack Checklist
• HHS - Cyber-Attack Response Infographic
• NIST - Data Integrity Publication
• NIST - Guide for Cybersecurity Event Recovery
• NIST - Identifying and Protecting Assets Against Ransomware and Other Destructive Events
• NIST - Detecting and Responding to Ransomware and Other Destructive Events
• NIST - Recovering from Ransomware and Other Destructive Events
• Github List of IOCs

Revisions

• October 28, 2020: Initial version
• October 29, 2020: Updated to include information on Conti, TrickBot, and BazarLoader, including new IOCs and Yara Rules for detection
• November 2, 2020: Updated FBI link

AA20-301A: North Korean Advanced Persistent Threat Focus: Kimsuky
Original release date: October 27, 2020

Summary

This advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) version 7 framework. See the ATT&CK for Enterprise version 7 for all referenced threat actor tactics and techniques.

This joint cybersecurity advisory was coauthored by the Cybersecurity and Infrastructure Security Agency (CISA), the Federal Bureau of Investigation (FBI), and the U.S. Cyber Command Cyber National Mission Force (CNMF). This advisory describes the tactics, techniques, and procedures (TTPs) used by North Korean advanced persistent threat (APT) group Kimsuky—against worldwide targets—to gain intelligence on various topics of interest to the North Korean government. The U.S. Government refers to malicious cyber activity by the North Korean government as HIDDEN COBRA. For more information on HIDDEN COBRA activity, visit https://www.us-cert.cisa.gov/northkorea.

This advisory describes known Kimsuky TTPs, as found in open-source and intelligence reporting through July 2020. The target audience for this advisory is commercial sector businesses desiring to protect their networks from North Korean APT activity.

Click here for a PDF version of this report.

Key Findings

This advisory’s key findings are:

• The Kimsuky APT group has most likely been operating since 2012.
• Kimsuky is most likely tasked by the North Korean regime with a global intelligence gathering mission.
• Kimsuky employs common social engineering tactics, spearphishing, and watering hole attacks to exfiltrate desired information from victims.[1],[2]
• Kimsuky is most likely to use spearphishing to gain initial access into victim hosts or networks.[3]
• Kimsuky conducts its intelligence collection activities against individuals and organizations in South Korea, Japan, and the United States.
• Kimsuky focuses its intelligence collection activities on foreign policy and national security issues related to the Korean peninsula, nuclear policy, and sanctions.
• Kimsuky specifically targets:
• • Individuals identified as experts in various fields,
  • Think tanks, and
  • South Korean government entities.[4],[5],[6],[7],[8]
• CISA, FBI, and CNMF recommend individuals and organizations within this target profile increase their defenses and adopt a heightened state of awareness. Particularly important mitigations include safeguards against spearphishing, use of multi-factor authentication, and user awareness training.

Technical Details

Initial Access

Kimsuky uses various spearphishing and social engineering methods to obtain Initial Access [TA0001] to victim networks.[9],[10],[11] Spearphishing—with a malicious attachment embedded in the email—is the most observed Kimsuky tactic (Phishing: Spearphishing Attachment [T1566.001]).[12],[13]

• The APT group has used web hosting credentials—stolen from victims outside of their usual targets—to host their malicious scripts and tools. Kimsuky likely obtained the credentials from the victims via spearphishing and credential harvesting scripts. On the victim domains, they have created subdomains mimicking legitimate sites and services they are spoofing, such as Google or Yahoo mail.[14]
• Kimsuky has also sent benign emails to targets, which were possibly intended to build trust in advance of a follow-on email with a malicious attachment or link.
  • Posing as South Korean reporters, Kimsuky exchanged several benign interview-themed emails with their intended target to ostensibly arrange an interview date and possibly build rapport. The emails contained the subject line “Skype Interview requests of [Redacted TV Show] in Seoul,” and began with a request to have the recipient appear as a guest on the show. The APT group invited the targets to a Skype interview on the topic of inter-Korean issues and denuclearization negotiations on the Korean Peninsula.
  • After a recipient agreed to an interview, Kimsuky sent a subsequent email with a malicious document, either as an attachment or as a Google Drive link within the body. The document usually contained a variant of BabyShark malware (see the Execution section for information on BabyShark). When the date of the interview drew near, Kimsuky sent an email canceling the interview.
• Kimsuky tailors its spearphishing and social engineering approaches to use topics relevant to the target, such as COVID-19, the North Korean nuclear program, or media interviews.[15],[16],[17]

Kimsuky’s other methods for obtaining initial access include login-security-alert-themed phishing emails, watering hole attacks, distributing malware through torrent sharing sites, and directing victims to install malicious browser extensions (Phishing: Spearphising Link [T1566.002], Drive-by Compromise [T1189], Man-in-the-Browser [T1185]).[18]

Execution

After obtaining initial access, Kimsuky uses BabyShark malware and PowerShell or the Windows Command Shell for Execution [TA0002].

• BabyShark is Visual Basic Script (VBS)-based malware.
  • First, the compromised host system uses the native Microsoft Windows utility, mshta.exe, to download and execute an HTML application (HTA) file from a remote system (Signed Binary Proxy Execution: Mshta [T1218.005]).
  • The HTA file then downloads, decodes, and executes the encoded BabyShark VBS file.
  • The script maintains Persistence [TA0003] by creating a Registry key that runs on startup (Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder [T1547.001]).
  •  It then collects system information (System Information Discovery [T1082]), sends it to the operator’s command control (C2) servers, and awaits further commands.[19],[20],[21],[22]
• Open-source reporting indicates BabyShark is delivered via an email message containing a link or an attachment (see Initial Access section for more information) (Phishing: Spearphising Link [T1566.002], Phishing: Spearphishing Attachment [T1566.001]). Kimsuky tailors email phishing messages to match its targets’ interests. Observed targets have been U.S. think tanks and the global cryptocurrency industry.[23]
• Kimsuky uses PowerShell to run executables from the internet without touching the physical hard disk on a computer by using the target’s memory (Command and Scripting Interpreter: PowerShell [T1059.001]). PowerShell commands/scripts can be executed without invoking powershell.exe through HTA files or mshta.exe.[24],[25],[26],[27]

Persistence

Kimsuky has demonstrated the ability to establish Persistence [TA0003] through using malicious browser extensions, modifying system processes, manipulating the autostart execution, using Remote Desktop Protocol (RDP), and changing the default file association for an application. By using these methods, Kimsuky can gain login and password information and/or launch malware outside of some application allowlisting solutions.

• In 2018, Kimsuky used an extension, which was available on the Google Chrome Web Store, to infect victims and steal passwords and cookies from their browsers (Man-in-the-Browser [T1185]). The extension’s reviews gave it a five-star rating, however the text of the reviews applied to other extensions or was negative. The reviews were likely left by compromised Google+ accounts.[28]
• Kimsuky may install a new service that can execute at startup by using utilities to interact with services or by directly modifying the Registry keys (Boot or Logon Autostart Execution [T1547]). The service name may be disguised with the name from a related operating system function or by masquerading as benign software. Services may be created with administrator privileges but are executed under system privileges, so an adversary can also use a service to escalate privileges from Administrator to System. They can also directly start services through Service Execution.[29],[30]
• During the STOLEN PENCIL operation in May 2018, Kimsuky used the GREASE malware. GREASE is a tool capable of adding a Windows administrator account and enabling RDP while avoiding firewall rules (Remote Services: Remote Desktop Protocol [T1021.001]).[31]
• Kimsuky uses a document stealer module that changes the default program associated with Hangul Word Processor (HWP) documents (.hwp files) in the Registry (Event Triggered Execution: Change Default File Association [T1546.001]). Kimsuky manipulates the default Registry setting to open a malicious program instead of the legitimate HWP program (HWP is a Korean word processor). The malware will read and email the content from HWP documents before the legitimate HWP program ultimately opens the document.[32] Kimsuky also targets Microsoft Office users by formatting their documents in a .docx file rather than .hwp and will tailor their macros accordingly.[33]
• Kimsuky maintains access to compromised domains by uploading actor-modified versions of open-source Hypertext Processor (PHP)-based web shells; these web shells enable the APT actor to upload, download, and delete files and directories on the compromised domains (Server Software Component: Web Shell [T1505.003]). The actor often adds “Dinosaur” references within the modified web shell codes.[34]

Privilege Escalation

Kimsuky uses well-known methods for Privilege Escalation [TA0004]. These methods include placing scripts in the Startup folder, creating and running new services, changing default file associations, and injecting malicious code in explorer.exe.

• Kimsuky has used Win7Elevate—an exploit from the Metasploit framework—to bypass the User Account Control to inject malicious code into explorer.exe (Process Injection [T1055]). This malicious code decrypts its spying library—a collection of keystroke logging and remote control access tools and remote control download and execution tools—from resources, regardless of the victim’s operating system. It then saves the decrypted file to a disk with a random but hardcoded name (e.g., dfe8b437dd7c417a6d.tmp) in the user’s temporary folder and loads this file as a library, ensuring the tools are then on the system even after a reboot. This allows for the escalation of privileges.[35]
• Before the injection takes place, the malware sets the necessary privileges (see figure 1). The malware writes the path to its malicious Dynamic Link Library (DLL) and ensures the remote process is loaded by creating a remote thread within explorer.exe (Process Injection [T1055]).[36]

Figure 1: Privileges set for the injection [37]

Defense Evasion

Kimsuky uses well-known and widely available methods for Defense Evasion [TA0005] within a network. These methods include disabling security tools, deleting files, and using Metasploit.[38],[39]

• Kimsuky’s malicious DLL runs at startup to zero (i.e., turn off) the Windows firewall Registry keys (see figure 2). This disables the Windows system firewall and turns off the Windows Security Center service, which prevents the service from alerting the user about the disabled firewall (see figure 2) (Impair Defenses: Disable or Modify System Firewall [T1562.004]).[40]

Figure 2: Disabled firewall values in the Registry [41]

• Kimsuky has used a keylogger that deletes exfiltrated data on disk after it is transmitted to its C2 server (Indicator Removal on Host: File Deletion [T1070.004]).[42]
• Kimsuky has used mshta.exe, which is a utility that executes Microsoft HTAs. It can be used for proxy execution of malicious .hta files and JavaScript or VBS through a trusted windows utility (Signed Binary Proxy Execution: Mshta [T1218.005]). It can also be used to bypass application allow listing solutions (Abuse Elevation Control Mechanism: Bypass User Access Control [T1548.002]).[43],[44]
• Win7Elevate—which was noted above—is also used to evade traditional security measures. Win7Elevatve is a part of the Metasploit framework open-source code and is used to inject malicious code into explorer.exe (Process Injection [T1055]). The malicious code decrypts its spying library from resources, saves the decrypted file to disk with a random but hardcoded name in the victim's temporary folder, and loads the file as a library.[45],[46],[47]

Credential Access

Kimsuky uses legitimate tools and network sniffers to harvest credentials from web browsers, files, and keyloggers (Credential Access [TA0006]).

• Kimsuky uses memory dump programs instead of using well-known malicious software and performs the credential extraction offline. Kimsuky uses ProcDump, a Windows command line administration tool, also available for Linux, that allows a user to create crash dumps/core dumps of processes based upon certain criteria, such as high central processing unit (CPU) utilization (OS Credential Dumping [T1003]). ProcDump monitors for CPU spikes and generates a crash dump when a value is met; it passes information to a Word document saved on the computer. It can be used as a general process dump utility that actors can embed in other scripts, as seen by Kimsuky’s inclusion of ProcDump in the BabyShark malware.[48]
• According to open-source security researchers, Kimsuky abuses a Chrome extension to steal passwords and cookies from browsers (Man-in-the-Browser [T1185]).[49],[50] The spearphishing email directs a victim to a phishing site, where the victim is shown a benign PDF document but is not able to view it. The victim is then redirected to the official Chrome Web Store page to install a Chrome extension, which has the ability to steal cookies and site passwords and loads a JavaScript file, named jQuery.js, from a separate site (see figure 3).[51]

Figure 3: JavaScript file, named jQuery.js [52]

• Kimsuky also uses a PowerShell based keylogger, named MECHANICAL, and a network sniffing tool, named Nirsoft SniffPass (Input Capture: Keylogging [T1056.001], Network Sniffing [T1040]). MECHANICAL logs keystrokes to %userprofile%\appdata\roaming\apach.{txt,log} and is also a "cryptojacker," which is a tool that uses a victim’s computer to mine cryptocurrency. Nirsoft SniffPass is capable of obtaining passwords sent over non-secure protocols.[53]
• Kimsuky used actor-modified versions of PHProxy, an open-source web proxy written in PHP, to examine web traffic between the victim and the website accessed by the victims and to collect any credentials entered by the victim.[54]

Discovery

Kimsuky enumerates system information and the file structure for victims’ computers and networks (Discovery [TA0007]). Kimsuky appears to rely on using the victim’s operating system command prompt to enumerate the file structure and system information (File and Directory Discovery [T1083]). The information is directed to C:\WINDOWS\msdatl3.inc, read by malware, and likely emailed to the malware’s command server.[55]

Collection

Kimsuky collects data from the victim system through its HWP document malware and its keylogger (Collection [TA0009]). The HWP document malware changes the default program association in the Registry to open HWP documents (Event Triggered Execution: Change Default File Association [T1546.001]). When a user opens an HWP file, the Registry key change triggers the execution of malware that opens the HWP document and then sends a copy of the HWP document to an account under the adversary’s control. The malware then allows the user to open the file as normal without any indication to the user that anything has occurred. The keylogger intercepts keystrokes and writes them to C:\Program Files\Common Files\System\Ole DB\msolui80.inc and records the active window name where the user pressed keys (Input Capture: Keylogging [T1056.001]). There is another keylogger variant that logs keystrokes into C:\WINDOWS\setup.log.[56]

Kimsuky has also used a Mac OS Python implant that gathers data from Mac OS systems and sends it to a C2 server (Command and Scripting Interpreter: Python [T1059.006]). The Python program downloads various implants based on C2 options specified after the filedown.php (see figure 4).

Figure 4: Python Script targeting MacOS [57]

Command and Control

Kimsuky has used a modified TeamViewer client, version 5.0.9104, for Command and Control [TA0011] (Remote Access Software [T1219]). During the initial infection, the service “Remote Access Service” is created and adjusted to execute C:\Windows\System32\vcmon.exe at system startup (Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder [T1547.001]). Every time vcmon.exe is executed, it disables the firewall by zeroing out Registry values (Impair Defenses: Disable or Modify System Firewall [T1562.004]). The program then modifies the TeamViewer Registry settings by changing the TeamViewer strings in TeamViewer components. The launcher then configures several Registry values, including SecurityPasswordAES, that control how the remote access tool will work. The SecurityPasswordAES Registry value represents a hash of the password used by a remote user to connect to TeamViewer Client (Use Alternate Authentication Material: Pass the Hash [T1550.002]). This way, the attackers set a pre-shared authentication value to have access to the TeamViewer Client. The attacker will then execute the TeamViewer client netsvcs.exe.[58]

Kimsuky has been using a consistent format. In the URL used recently—express[.]php?op=1—there appears to be an option range from 1 to 3.[59]

Exfiltration

Open-source reporting from cybersecurity companies describes two different methods Kimsuky has used to exfiltrate stolen data: via email or through an RC4 key generated as an MD5 hash or a randomly generated 117-bytes buffer (Exfiltration [TA0010]).

There was no indication that the actor destroyed computers during the observed exfiltrations, suggesting Kimsuky’s intention is to steal information, not to disrupt computer networks. Kimsuky’s preferred method for sending or receiving exfiltrated information is through email, with their malware on the victim machine encrypting the data before sending it to a C2 server (Archive Collected Data [T1560]).  Kimsuky also sets up auto-forward rules within a victim’s email account (Email Collection: Email Forwarding Rule [T1114.003]).

Kimsuky also uses an RC4 key generated as an MD5 hash or a randomly generated 117-bytes buffer to exfiltrate stolen data. The data is sent RSA-encrypted (Encrypted Channel: Symmetric Cryptography [T1573.001]). Kimsuky’s malware constructs an 1120-bit public key and uses it to encrypt the 117-bytes buffer. The resulting data file is saved in C:\Program Files\Common Files\System\Ole DB\ (Data Staged: Local Data Staging [T1074.001]).[60]

Mitigations

Indicators of Compromise

Kimsuky has used the domains listed in table 1 to carry out its objectives:

For a downloadable copy of IOCs, see AA20-301A.stix.

Table 1: Domains used by Kimsuky

Table 2: Redacted domains used by Kimsuky

Contact Information

To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at www.fbi.gov/contact-us/field, or the FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by e-mail at CyWatch@fbi.gov. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact. To request incident response resources or technical assistance related to these threats, contact CISA at Central@cisa.dhs.gov.

References

• [1] Netscout: Stolen Pencil Campaign Targets Academia
• [2] CYWARE Social: Babyshark malware continues to target nuclear and cryptocurrency industries
• [3] CYWARE Social: Babyshark malware continues to target nuclear and cryptocurrency industries
• [4] Netscout: Stolen Pencil Campaign Targets Academia
• [5] MITRE ATT&CK: Groups – Kimsuky
• [6] Securityweek.com: North Korean Suspected Cyber-espionage Attacks Against South Korea Entities
• [7] MITRE ATT&CK: Groups – Kimsuky
• [8] CrowdStrike: 2020 Global Threat Report
• [9] Malwarebytes: APTs and COVID-19: How advanced persistent threats use the coronavirus as a lure
• [10] PwC: Tracking ‘Kimsuky’, the North Korea-based cyber espionage group: Part 2
• [11] CrowdStrike: 2020 Global Threat Report
• [12] Netscout: Stolen Pencil Campaign Targets Academia
• [13] MITRE ATT&CK: Groups – Kimsuky
• [14] Private Sector Partner
• [15] CYWARE Social: Babyshark malware continues to target nuclear and cryptocurrency industries
• [16] Malwarebytes: APTs and COVID-19: How advanced persistent threats use the coronavirus as a lure
• [17] cyberscoop: North Korea could accelerate commercial espionage to meet Kim’s economic deadline
• [18] MITRE ATT&CK: Groups – Kimsuky
• [19] CYWARE Social: Babyshark malware continues to target nuclear and cryptocurrency industries
• [20] MITRE ATT&CK: Groups – Kimsuky
• [21] Palo Alto Networks Unit 42: New BabyShark Malware Targets U.S. National Security Think Tanks
• [22] Palo Alto Networks Unit 42: New BabyShark Malware Targets U.S. National Security Think Tanks
• [23] CYWARE Social: Babyshark malware continues to target nuclear and cryptocurrency industries
• [24] MITRE ATT&CK: Groups – Kimsuky
• [25] Palo Alto Networks Unit 42: BabyShark Malware Part Two – Attacks Continue Using KimJongRAT and PCRat
• [26] McAfee: What is mshta, how can it be used and how to protect against it
• [27] Palo Alto Networks Unit 42: New BabyShark Malware Targets U.S. National Security Think Tanks
• [28] Netscout: Stolen Pencil Campaign Targets Academia
• [29] MITRE ATT&CK: Groups – Kimsuky
• [30] Palo Alto Networks Unit 42: New BabyShark Malware Targets U.S. National Security Think Tanks
• [31] Netscout: Stolen Pencil Campaign Targets Academia
• [32] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [33] Private Sector Partner
• [34] Private Sector Partner
• [35] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [36] Yoroi: The North Korean Kimsuky APT Keeps Threatening South Korea Evolving its TTPs
• [37] Yoroi: The North Korean Kimsuky APT Keeps Threatening South Korea Evolving its TTPs
• [38] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [39] MITRE ATT&CK: Groups – Kimsuky
• [40] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [41] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [42] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [43] MITRE ATT&CK: Groups – Kimsuky
• [44] McAfee: What is mshta, how can it be used and how to protect against it
• [45] Securityweek.com: North Korean Suspected Cyber-espionage Attacks Against South Korea Entities
• [46] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [47] MITRE ATT&CK: Groups – Kimsuky
• [48] Detecting credential theft through memory access modelling with Microsoft Defender ATP
• [49] MITRE ATT&CK: Groups – Kimsuky
• [50] ZDNet: Cyber-espionage-group-uses-chrome-extension-to-infect-victims
• [51] ZDNet: Cyber-espionage-group-uses-chrome-extension-to-infect-victims
• [52] Netscout: Stolen Pencil Campaign Targets Academia
• [53] Netscout: Stolen Pencil Campaign Targets Academia
• [54] Private Sector Partner
• [55] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [56] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [57] Private Sector Partner
• [58] Securelist: The “Kimsuky” Operation: A North Korean APT?
• [59] Private Sector Partner
• [60] Securelist: The “Kimsuky” Operation: A North Korean APT?

Revisions

• October 27, 2020: Initial Version