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This report is provided “as is” for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained herein. The DHS does not endorse any commercial product or service referenced in this bulletin or otherwise.

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 (TLP), see http://www.us-cert.gov/tlp.

Description

This Malware Analysis Report (MAR) is the result of analytic efforts between the Department of Homeland Security (DHS), the Federal Bureau of Investigation (FBI), and the Department of Defense (DoD). Working with U.S. Government partners, DHS, FBI, and DoD identified Remote Access Tool (RAT) malware variants used by the North Korean government. This malware variant has been identified as ECCENTRICBANDWAGON. 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.gov/hiddencobra.

FBI has high confidence that HIDDEN COBRA actors are using malware variants in conjunction with proxy servers to maintain a presence on victim networks and to further network exploitation. DHS, FBI, and DoD are distributing this MAR to enable network defense and reduce exposure to North Korean government malicious cyber activity.

This MAR includes malware descriptions related to HIDDEN COBRA, suggested response actions and recommended mitigation techniques. Users or administrators should flag activity associated with the malware and report the activity to the Cybersecurity and Infrastructure Security Agency (CISA) or the FBI Cyber Watch (CyWatch), and give the activity the highest priority for enhanced mitigation.

This report looks at malware samples known as ECCENTRICBANDWAGON. This family of malware is used as a reconnaissance tool. The samples in this report are used for keylogging and screen capture functionality. The samples are very similar, but differ slightly in the location that they store the key logs and screenshots. Some variants have RC4 encrypted strings within the executable and conduct a simple, ineffective cleanup, whereas others do not.

For a downloadable copy of IOCs, see MAR-10301706-1.v1.stix.

Submitted Files (4)

32a4de070ca005d35a88503717157b0dc3f2e8da76ffd618fca6563aec9c81f8 (PSLogger .dll)

9ea5aa00e0a738b74066c61b1d35331170a9e0a84df1cc6cef58fd46a8ec5a2e (PSLogger .dll)

c6930e298bba86c01d0fe2c8262c46b4fce97c6c5037a193904cfc634246fbec (PSLogger .dll)

efd470cfa90b918e5d558e5c8c3821343af06eedfd484dfeb20c4605f9bdc30e (PSLogger .dll)

efd470cfa90b918e5d558e5c8c3821343af06eedfd484dfeb20c4605f9bdc30e

Tags

HIDDEN-COBRAbackdoorkeyloggerreconnaissancescreen-capturespywaretrojan

Details

Antivirus

YARA Rules

• rule CISA_3P_10301706_01 : HiddenCobra ECCENTRICBANDWAGON backdoor keylogger reconnaissance screencapture spyware trojan
  {
     meta:
         Author = “CISA Trusted Third Party”
         Incident = “10301706.r1.v1”
         Date = “2020-08-11”
         Actor = “Hidden Cobra”
         Category = “Backdoor Keylogger Reconnaissance Screen-Capture Spyware Trojan”
         Family = “ECCENTRICBANDWAGON”
         Description = “Detects strings in ECCENTRICBANDWAGON proxy tool”
         MD5_1 = “d45931632ed9e11476325189ccb6b530”
         SHA256_1 = “efd470cfa90b918e5d558e5c8c3821343af06eedfd484dfeb20c4605f9bdc30e”
         MD5_2 = “acd15f4393e96fe5eb920727dc083aed”
         SHA256_2 = “32a4de070ca005d35a88503717157b0dc3f2e8da76ffd618fca6563aec9c81f8”
         MD5_3 = “34404a3fb9804977c6ab86cb991fb130”
         SHA256_3 = “c6930e298bba86c01d0fe2c8262c46b4fce97c6c5037a193904cfc634246fbec”
         MD5_4 = “3122b0130f5135b6f76fca99609d5cbe”
         SHA256_4 = “9ea5aa00e0a738b74066c61b1d35331170a9e0a84df1cc6cef58fd46a8ec5a2e”
     strings:
         $sn1 = { FB 19 9D 57 [1-6] 9A D1 D6 D1 [1-6] 42 9E D8 FD }
         $sn2 = { 4F 03 43 83 [1-6] 48 E0 1A 2E [1-6] 3B FD FD FD }
         $sn3 = { 68 56 68 9A [1-12] 4D E1 1F 25 [1-12] 3F 38 54 0F [1-12] 73 30 62 A1 [1-12] DB 39 BD 56 }
         $sn4 = “%s\chromeupdater_ps_%04d%02d%02d_%02d%02d%02d_%03d_%d” wide ascii nocase
         $sn5 = “c:\windows\temp\TMP0389A.tmp” wide ascii nocase
     condition:
         any of them
  }

ssdeep Matches

PE Metadata

PE Sections

Description

This file is a 64-bit dynamic link library (DLL). This malware uses 3 files that will be used to store the key logs, screen shots, and log intervals. The location of these logs can be found in C:windowstempTMP0389A.tmp.

–Begin Log Files–
1. Keylog: %temp%GoogleChromechromeupdate_pk
2. Screenshots: %temp%GoogleChromechromeupdate_ps_<YYYMMDD>_<HHMMSS>_<sss>_<ThreadID>
3. Log intervals: C:ProgramData2.dat
–End Log Files–

The malware creates 3 threads to populate the log files listed above. Each one will continue to execute until a global kill variable is set to 1. This variable can only be set to 1 by calling an export called “Process” from within this DLL. When the export is called, the threads will return and the program will exit.

32a4de070ca005d35a88503717157b0dc3f2e8da76ffd618fca6563aec9c81f8

Tags

HIDDEN-COBRAbackdoorkeyloggerreconnaissancescreen-capturespywaretrojan

Details

Antivirus

YARA Rules

• rule CISA_3P_10301706_01 : HiddenCobra ECCENTRICBANDWAGON backdoor keylogger reconnaissance screencapture spyware trojan
  {
     meta:
         Author = “CISA Trusted Third Party”
         Incident = “10301706.r1.v1”
         Date = “2020-08-11”
         Actor = “Hidden Cobra”
         Category = “Backdoor Keylogger Reconnaissance Screen-Capture Spyware Trojan”
         Family = “ECCENTRICBANDWAGON”
         Description = “Detects strings in ECCENTRICBANDWAGON proxy tool”
         MD5_1 = “d45931632ed9e11476325189ccb6b530”
         SHA256_1 = “efd470cfa90b918e5d558e5c8c3821343af06eedfd484dfeb20c4605f9bdc30e”
         MD5_2 = “acd15f4393e96fe5eb920727dc083aed”
         SHA256_2 = “32a4de070ca005d35a88503717157b0dc3f2e8da76ffd618fca6563aec9c81f8”
         MD5_3 = “34404a3fb9804977c6ab86cb991fb130”
         SHA256_3 = “c6930e298bba86c01d0fe2c8262c46b4fce97c6c5037a193904cfc634246fbec”
         MD5_4 = “3122b0130f5135b6f76fca99609d5cbe”
         SHA256_4 = “9ea5aa00e0a738b74066c61b1d35331170a9e0a84df1cc6cef58fd46a8ec5a2e”
     strings:
         $sn1 = { FB 19 9D 57 [1-6] 9A D1 D6 D1 [1-6] 42 9E D8 FD }
         $sn2 = { 4F 03 43 83 [1-6] 48 E0 1A 2E [1-6] 3B FD FD FD }
         $sn3 = { 68 56 68 9A [1-12] 4D E1 1F 25 [1-12] 3F 38 54 0F [1-12] 73 30 62 A1 [1-12] DB 39 BD 56 }
         $sn4 = “%s\chromeupdater_ps_%04d%02d%02d_%02d%02d%02d_%03d_%d” wide ascii nocase
         $sn5 = “c:\windows\temp\TMP0389A.tmp” wide ascii nocase
     condition:
         any of them
  }

ssdeep Matches

PE Metadata

PE Sections

Description

This file is a 64-bit DLL. This sample and “efd470cfa90b918e5d558e5c8c3821343af06eedfd484dfeb20c4605f9bdc30e” are nearly identical with the only difference being that this sample has 3 extra NULL bytes at the end of the file.

This malware uses 3 files that will be used to store the key logs, screen shots, and log intervals. The location of these logs can be found in C:windowstempTMP0389A.tmp.

–Begin Log Files–
1. Keylog: %temp%GoogleChromechromeupdate_pk
2. Screenshots: %temp%GoogleChromechromeupdate_ps_<YYYMMDD>_<HHMMSS>_<sss>_<ThreadID>
3. Log intervals: C:ProgramData2.dat
–End Log Files–

The malware creates 3 threads to populate the log files listed above. Each one will continue to execute until a global kill variable is set to 1. This variable can only be set to 1 by calling an export called “Process” from within this DLL. When the export is called, the threads will return and the program will exit.

c6930e298bba86c01d0fe2c8262c46b4fce97c6c5037a193904cfc634246fbec

Tags

HIDDEN-COBRAbackdoorkeyloggerreconnaissancescreen-capturetrojan

Details

Antivirus

YARA Rules

• rule CISA_3P_10301706_01 : HiddenCobra ECCENTRICBANDWAGON backdoor keylogger reconnaissance screencapture spyware trojan
  {
     meta:
         Author = “CISA Trusted Third Party”
         Incident = “10301706.r1.v1”
         Date = “2020-08-11”
         Actor = “Hidden Cobra”
         Category = “Backdoor Keylogger Reconnaissance Screen-Capture Spyware Trojan”
         Family = “ECCENTRICBANDWAGON”
         Description = “Detects strings in ECCENTRICBANDWAGON proxy tool”
         MD5_1 = “d45931632ed9e11476325189ccb6b530”
         SHA256_1 = “efd470cfa90b918e5d558e5c8c3821343af06eedfd484dfeb20c4605f9bdc30e”
         MD5_2 = “acd15f4393e96fe5eb920727dc083aed”
         SHA256_2 = “32a4de070ca005d35a88503717157b0dc3f2e8da76ffd618fca6563aec9c81f8”
         MD5_3 = “34404a3fb9804977c6ab86cb991fb130”
         SHA256_3 = “c6930e298bba86c01d0fe2c8262c46b4fce97c6c5037a193904cfc634246fbec”
         MD5_4 = “3122b0130f5135b6f76fca99609d5cbe”
         SHA256_4 = “9ea5aa00e0a738b74066c61b1d35331170a9e0a84df1cc6cef58fd46a8ec5a2e”
     strings:
         $sn1 = { FB 19 9D 57 [1-6] 9A D1 D6 D1 [1-6] 42 9E D8 FD }
         $sn2 = { 4F 03 43 83 [1-6] 48 E0 1A 2E [1-6] 3B FD FD FD }
         $sn3 = { 68 56 68 9A [1-12] 4D E1 1F 25 [1-12] 3F 38 54 0F [1-12] 73 30 62 A1 [1-12] DB 39 BD 56 }
         $sn4 = “%s\chromeupdater_ps_%04d%02d%02d_%02d%02d%02d_%03d_%d” wide ascii nocase
         $sn5 = “c:\windows\temp\TMP0389A.tmp” wide ascii nocase
     condition:
         any of them
  }

ssdeep Matches

No matches found.

PE Metadata

PE Sections

Packers/Compilers/Cryptors

Description

This sample is nearly identical to “efd470cfa90b918e5d558e5c8c3821343af06eedfd484dfeb20c4605f9bdc30e” with the exception that this sample will RC4 encrypt some of its strings and use different log files.

The following strings are RC4 encrypted with the key “key”:

–Begin RC4 encrypted strings–
Downloads
c:windowstempTMP0389A.tmp
c:windowstemptmp1105.tmp
[CLIPBOARD]
[/CLIPBOARD]
–End RC4 encrypted strings–

This malware uses 3 files that will be used to store the key logs, screen shots, and log intervals. The location of these logs can be found in C:windowstempTMP0389A.tmp.

–Begin log files–
1. Keylog: %temp%Downloadstmp_<USERNAME>
2. Screenshots: %temp%Downloadstmp_<USERNAME>_<MMDD>_<HHMMSS>
3. Log intervals: c:windowstemptmp1105.tmp
–End log files–

The malware creates 3 threads to populate the log files listed above. Each one will continue to execute until a global kill variable is set to 1. This variable can only be set to 1 by calling an export called “Process” from within this DLL. When the export is called, the threads will return and the program will exit.

9ea5aa00e0a738b74066c61b1d35331170a9e0a84df1cc6cef58fd46a8ec5a2e

Tags

HIDDEN-COBRAkeyloggerreconnaissancescreen-capturespywaretrojan

Details

Antivirus

YARA Rules

• rule CISA_3P_10301706_01 : HiddenCobra ECCENTRICBANDWAGON backdoor keylogger reconnaissance screencapture spyware trojan
  {
     meta:
         Author = “CISA Trusted Third Party”
         Incident = “10301706.r1.v1”
         Date = “2020-08-11”
         Actor = “Hidden Cobra”
         Category = “Backdoor Keylogger Reconnaissance Screen-Capture Spyware Trojan”
         Family = “ECCENTRICBANDWAGON”
         Description = “Detects strings in ECCENTRICBANDWAGON proxy tool”
         MD5_1 = “d45931632ed9e11476325189ccb6b530”
         SHA256_1 = “efd470cfa90b918e5d558e5c8c3821343af06eedfd484dfeb20c4605f9bdc30e”
         MD5_2 = “acd15f4393e96fe5eb920727dc083aed”
         SHA256_2 = “32a4de070ca005d35a88503717157b0dc3f2e8da76ffd618fca6563aec9c81f8”
         MD5_3 = “34404a3fb9804977c6ab86cb991fb130”
         SHA256_3 = “c6930e298bba86c01d0fe2c8262c46b4fce97c6c5037a193904cfc634246fbec”
         MD5_4 = “3122b0130f5135b6f76fca99609d5cbe”
         SHA256_4 = “9ea5aa00e0a738b74066c61b1d35331170a9e0a84df1cc6cef58fd46a8ec5a2e”
     strings:
         $sn1 = { FB 19 9D 57 [1-6] 9A D1 D6 D1 [1-6] 42 9E D8 FD }
         $sn2 = { 4F 03 43 83 [1-6] 48 E0 1A 2E [1-6] 3B FD FD FD }
         $sn3 = { 68 56 68 9A [1-12] 4D E1 1F 25 [1-12] 3F 38 54 0F [1-12] 73 30 62 A1 [1-12] DB 39 BD 56 }
         $sn4 = “%s\chromeupdater_ps_%04d%02d%02d_%02d%02d%02d_%03d_%d” wide ascii nocase
         $sn5 = “c:\windows\temp\TMP0389A.tmp” wide ascii nocase
     condition:
         any of them
  }

ssdeep Matches

No matches found.

PE Metadata

PE Sections

Description

This sample is nearly identical to “c6930e298bba86c01d0fe2c8262c46b4fce97c6c5037a193904cfc634246fbec” with the exception that it RC4 encrypts some of its strings, uses different log files, and has a simple cleanup routine.

The following strings are RC4 encrypted with the key “key”:

–Begin RC4 encrypted strings–
TrendMicroUpdate
c:windowstempTMP0389A.tmp
c:windowstemptmp1105.tmp
[CLIPBOARD]
[/CLIPBOARD]
–End RC4 encrypted strings–

This malware uses 3 files that will be used to store the key logs, screen shots, and log intervals. The location of these logs can be found in C:windowstempTMP0389A.tmp.

–Begin log files–
1. Keylog: %temp%TrendMicroUpdateupdate_<USERNAME>
2. Screenshots: %temp%TrendMicroUpdateupdate_<MMDD>_<HHMMSSl>
3. Log Intervals: c:windowstemptmp1105.tmp
–End log files–

This malware creates 3 threads to populate the log files listed above. Each one will continue to execute until the file C:windowstemptmp0207 contains a zero in a particular location. At this point, the program will signal an exit to the other threads and begin a cleanup thread. The cleanup thread will delete C:windowstemptmp0207 and then call WinExec(cmd.exe /c taskkill /f /im explorer.exe). This will crash explorer.exe, which could potentially alert a user who was using the device at the time.

CISA recommends that users and administrators consider using the following best practices to strengthen the security posture of their organization’s systems. Any configuration changes should be reviewed by system owners and administrators prior to implementation to avoid unwanted impacts.

• Maintain up-to-date antivirus signatures and engines.
• Keep operating system patches up-to-date.
• Disable File and Printer sharing services. If these services are required, use strong passwords or Active Directory authentication.
• Restrict users’ ability (permissions) to install and run unwanted software applications. Do not add users to the local administrators group unless required.
• Enforce a strong password policy and implement regular password changes.
• Exercise caution when opening e-mail attachments even if the attachment is expected and the sender appears to be known.
• Enable a personal firewall on agency workstations, configured to deny unsolicited connection requests.
• Disable unnecessary services on agency workstations and servers.
• Scan for and remove suspicious e-mail attachments; ensure the scanned attachment is its “true file type” (i.e., the extension matches the file header).
• Monitor users’ web browsing habits; restrict access to sites with unfavorable content.
• Exercise caution when using removable media (e.g., USB thumb drives, external drives, CDs, etc.).
• Scan all software downloaded from the Internet prior to executing.
• Maintain situational awareness of the latest threats and implement appropriate Access Control Lists (ACLs).

Additional information on malware incident prevention and handling can be found in National Institute of Standards and Technology (NIST) Special Publication 800-83, “Guide to Malware Incident Prevention & Handling for Desktops and Laptops”.

• 1-888-282-0870
• CISA Service Desk (UNCLASS)
• CISA SIPR (SIPRNET)
• CISA IC (JWICS)

CISA continuously strives to improve its products and services. You can help by answering a very short series of questions about this product at the following URL: https://www.cisa.gov/forms/feedback/

What is a MIFR? A Malware Initial Findings Report (MIFR) is intended to provide organizations with malware analysis in a timely manner. In most instances this report will provide initial indicators for computer and network defense. To request additional analysis, please contact CISA and provide information regarding the level of desired analysis.

What is a MAR? A Malware Analysis Report (MAR) is intended to provide organizations with more detailed malware analysis acquired via manual reverse engineering. To request additional analysis, please contact CISA and provide information regarding the level of desired analysis.

Can I edit this document? This document is not to be edited in any way by recipients. All comments or questions related to this document should be directed to the CISA at 1-888-282-0870 or CISA Service Desk.

Can I submit malware to CISA? Malware samples can be submitted via three methods:

• Web: https://malware.us-cert.gov
• E-Mail: submit@malware.us-cert.gov
• FTP: ftp.malware.us-cert.gov (anonymous)

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 CISA’s homepage at www.cisa.gov.