Archiv für November 2023

Notification

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:CLEAR–Recipients may share this information without restriction. Sources may use TLP:CLEAR 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:CLEAR information may be shared without restriction. For more information on the Traffic Light Protocol (TLP), see http://www.cisa.gov/tlp.

Summary

Description

Responding to the recently disclosed CVE-2023-4966, affecting Citrix NetScaler ADC and NetScaler Gateway appliances, CISA received four files for analysis that show files being used to save registry hives, dump the Local Security Authority Subsystem Service (LSASS) process memory to disk, and attempts to establish sessions via Windows Remote Management (WinRM). The files include:

• Windows Batch file (.bat)
• Windows Executable (.exe)
• Windows Dynamic Link Library (.dll)
• Python Script (.py)

For more information about this vulnerability, see Joint Cybersecurity Advisory #StopRansomware: LockBit 3.0 Ransomware Affiliates Exploit CVE 2023-4966 Citrix Bleed Vulnerability.

Download the PDF version of this report:

For a downloadable copy of IOCs associated with this MAR in JSON format, see:

Submitted Files (4)

17a27b1759f10d1f6f1f51a11c0efea550e2075c2c394259af4d3f855bbcc994 (a.dll)

906602ea3c887af67bcb4531bbbb459d7c24a2efcb866bcb1e3b028a51f12ae6 (a.py)

98e79f95cf8de8ace88bf223421db5dce303b112152d66ffdf27ebdfcdf967e9 (a.bat)

e557e1440e394537cca71ed3d61372106c3c70eb6ef9f07521768f23a0974068 (a.exe)

Findings

98e79f95cf8de8ace88bf223421db5dce303b112152d66ffdf27ebdfcdf967e9

Details

–>

Antivirus

No matches found.

YARA Rules

• rule CISA_10478915_01 : trojan installs_other_components
{
   meta:
       author = "CISA Code & Media Analysis"
       incident = "10478915"
       date = "2023-11-06"
       last_modified = "20231108_1500"
       actor = "n/a"
       family = "n/a"
       capabilities = "installs-other-components"
       malware_Type = "trojan"
       tool_type = "information-gathering"
       description = "Detects trojan .bat samples"
       sha256 = "98e79f95cf8de8ace88bf223421db5dce303b112152d66ffdf27ebdfcdf967e9"
   strings:
       $s1 = { 63 3a 5c 77 69 6e 64 6f 77 73 5c 74 61 73 6b 73 5c 7a 2e 74 78 74 }
       $s2 = { 72 65 67 20 73 61 76 65 20 68 6b 6c 6d 5c 73 79 73 74 65 6d 20 63 3a 5c 77 69 6e 64 6f 77 73 5c 74 61 73 6b 73 5c 65 6d }
       $s3 = { 6d 61 6b 65 63 61 62 20 63 3a 5c 75 73 65 72 73 5c 70 75 62 6c 69 63 5c 61 2e 70 6e 67 20 63 3a 5c 77 69 6e 64 6f 77 73 5c 74 61 73 6b 73 5c 61 2e 63 61 62 }
   condition:
       all of them
}

ssdeep Matches

No matches found.

Relationships

Description

This file is a Windows batch file called a.bat that is used to execute the file called a.exe with the file called a.dll as an argument. The output is printed to a file named ‚z.txt‘ located in the path C:WindowsTasks. Next, a.bat pings the loop back internet protocol (IP) address 127.0.0[.]1 three times.

The next command it runs is reg save to save the HKLMSYSTEM registry hive into the C:Windowstasksem directory. Again, a.bat pings the loop back address 127.0.0[.]1 one time before executing another reg save command and saves the HKLMSAM registry hive into the C:WindowsTaskam directory. Next, a.bat runs three makecab commands to create three Cabinet (.cab) files from the previously mentioned saved registry hives and one file named C:UsersPublica.png. The names of the .cab files are as follows:

–Start names and paths of .cab files created–
c:windowstasksem.cab
c:windowstasksam.cab
c:windowstasksa.cab
–End names and paths of .cab files created–

Screenshots

e557e1440e394537cca71ed3d61372106c3c70eb6ef9f07521768f23a0974068

Tags

trojan

Details

–>

Antivirus

YARA Rules

• rule CISA_10478915_02 : trojan installs_other_components
{
   meta:
       author = "CISA Code & Media Analysis"
       incident = "10478915"
       date = "2023-11-06"
       last_modified = "20231108_1500"
       actor = "n/a"
       family = "n/a"
       capabilities = "installs-other-components"
       malware_type = "trojan"
       tool_type = "unknown"
       description = "Detects trojan PE32 samples"
       sha256 = "e557e1440e394537cca71ed3d61372106c3c70eb6ef9f07521768f23a0974068"
   strings:
       $s1 = { 57 72 69 74 65 46 69 6c 65 }
       $s2 = { 41 70 70 50 6f 6c 69 63 79 47 65 74 50 72 6f 63 65 73 73 54 65 72 6d 69 6e 61 74 69 6f 6e 4d 65 74 68 6f 64 }
       $s3 = { 6f 70 65 72 61 74 6f 72 20 63 6f 5f 61 77 61 69 74 }
       $s4 = { 43 6f 6d 70 6c 65 74 65 20 4f 62 6a 65 63 74 20 4c 6f 63 61 74 6f 72 }
       $s5 = { 64 65 6c 65 74 65 5b 5d }
       $s6 = { 4e 41 4e 28 49 4e 44 29 }
   condition:
       uint16(0) == 0x5a4d and pe.imphash() == "6e8ca501c45a9b85fff2378cffaa24b2" and pe.size_of_code == 84480 and all of them
}

ssdeep Matches

No matches found.

Relationships

Description

This file is a 64-bit Windows command-line executable called a.exe that is executed by a.bat. This file issues the Remote Procedure Call (RPC) ncalrpc:[lsasspirpc] to the RPC end point to provide a file path to the LSASS on the infected machine. Once the file path is returned, the malware loads the accompanying DLL file called a.dll into the running LSASS process. If the DLL is correctly loaded, then the malware outputs the message „[*]success“ in the console.

17a27b1759f10d1f6f1f51a11c0efea550e2075c2c394259af4d3f855bbcc994

Tags

trojan

Details

–>

Antivirus

YARA Rules

• rule CISA_10478915_03 : trojan steals_authentication_credentials credential_exploitation
{
   meta:
       author = "CISA Code & Media Analysis"
       incident = "10478915"
       date = "2023-11-06"
       last_modified = "20231108_1500"
       actor = "n/a"
       family = "n/a"
       capabilities = "steals-authentication-credentials"
       malware_type = "trojan"
       tool_type = "credential-exploitation"
       description = "Detects trojan DLL samples"
       sha256 = "17a27b1759f10d1f6f1f51a11c0efea550e2075c2c394259af4d3f855bbcc994"
   strings:
       $s1 = { 64 65 6c 65 74 65 }
       $s2 = { 3c 2f 74 72 75 73 74 49 6e 66 6f 3e }
       $s3 = { 42 61 73 65 20 43 6c 61 73 73 20 44 65 73 63 72 69 70 74 6f 72 20 61 74 20 28 }
       $s4 = { 49 6e 69 74 69 61 6c 69 7a 65 43 72 69 74 69 63 61 6c 53 65 63 74 69 6f 6e 45 78 }
       $s5 = { 46 69 6e 64 46 69 72 73 74 46 69 6c 65 45 78 57 }
       $s6 = { 47 65 74 54 69 63 6b 43 6f 75 6e 74 }
   condition:
       uint16(0) == 0x5a4d and pe.subsystem == pe.SUBSYSTEM_WINDOWS_CUI and pe.size_of_code == 56832 and all of them
}

ssdeep Matches

No matches found.

Relationships

Description

This file is a 64-bit Windows DLL called a.dll that is executed by a.bat as a parameter for the file a.exe. The file a.exe loads this file into the running LSASS process on the infected machine. The file a.dll calls the Windows API CreateFileW to create a file called a.png in the path C:UsersPublic.

Next, a.dll loads DbgCore.dll then utilizes MiniDumpWriteDump function to dump LSASS process memory to disk. If successful, the dumped process memory is written to a.png. Once this is complete, the file a.bat specifies that the file a.png is used to create the cabinet file called a.cab in the path C:WindowsTasks.

Screenshots

906602ea3c887af67bcb4531bbbb459d7c24a2efcb866bcb1e3b028a51f12ae6

Details

–>

Antivirus

No matches found.

YARA Rules

• rule CISA_10478915_04 : backdoor communicates_with_c2 remote_access
{
   meta:
       author = "CISA Code & Media Analysis"
       incident = "10478915"
       date = "2023-11-06"
       last_modified = "20231108_1500"
       actor = "n/a"
       family = "n/a"
       capabilities = "communicates-with-c2"
       malware_type = "backdoor"
       tool_type = "remote-access"
       description = "Detects trojan python samples"
       sha256 = "906602ea3c887af67bcb4531bbbb459d7c24a2efcb866bcb1e3b028a51f12ae6"
   strings:
       $s1 = { 70 6f 72 74 20 3d 20 34 34 33 20 69 66 20 22 68 74 74 70 73 22 }
       $s2 = { 6b 77 61 72 67 73 2e 67 65 74 28 22 68 61 73 68 70 61 73 73 77 64 22 29 3a }
       $s3 = { 77 69 6e 72 6d 2e 53 65 73 73 69 6f 6e 20 62 61 73 69 63 20 65 72 72 6f 72 }
       $s4 = { 57 69 6e 64 77 6f 73 63 6d 64 2e 72 75 6e 5f 63 6d 64 28 73 74 72 28 63 6d 64 29 29 }
   condition:
       all of them
}

ssdeep Matches

No matches found.

Description

This file is a Python script called a.py that attempts to leverage WinRM to establish a session. The script attempts to authenticate to the remote machine using NT LAN Manager (NTLM) if the keyword „hashpasswd“ is present. If the keyword „hashpasswd“ is not present, then the script attempts to authenticate using basic authentication. Once a WinRM session is established with the remote machine, the script has the ability to execute command line arguments on the remote machine. If there is no command specified, then a default command of “whoami” is run.

Screenshots

Relationship Summary

Recommendations

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“.

Contact Information

• 1-844-Say-CISA
• contact@mail.cisa.dhs.gov (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://us-cert.cisa.gov/forms/feedback/

Document FAQ

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 SayCISA@cisa.dhs.gov or 1-844-Say-CISA.

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.

Notification

Summary

Findings

4183edae732506a18b5c802cbf0a471a77c3f1e4336a32ccb4958671e404493c

Details

–>

Name	machineecho_-n_Y2htb2QgK3ggL3Jvb3QvbWFjKgpzaCAvcm9vdC9tYWNoKlxgKgoK___base64_-d__sh_-slack
Size	3894 bytes
Type	data
MD5	9fdc1dc99bc8184ee410880427dba89c
SHA1	be570775552f937d8588bceb3e2cbb0c18408fc1
SHA256	4183edae732506a18b5c802cbf0a471a77c3f1e4336a32ccb4958671e404493c
SHA512	2bb94fdfe31a464c63b8cd726f6ba1c3b18da538221d5bae943dfb03ec353a41826bdcb007bc2b7dfeb76afe619aa8ce078808e9b30079a6f947cce8ace891ff
ssdeep	3::
Entropy	0.000000
Malware Result	unknown

Antivirus

No matches found.

YARA Rules

No matches found.

ssdeep Matches

No matches found.

Description

This file is a SUBMARINE artifact, an empty text/data file. The name of the file is designed to exploit a vulnerability on the target environment where the base64 string within the file name will be executed on the Linux shell. The code in Figure 1 will change the permissions of any directory/file/path with that begins with ‚/root/mac‘ to executable. Then, anything containing the string ‚mach*‘ in the directory/file/path ‚/root/mach‘ are executed.

Screenshots

 

63788797919985d0e567cf9133ad2ab7a1c415e81598dc07c0bfa3a1566aeb90

Details

–>

Name	get_fs_info.pl
Size	530 bytes
Type	Perl script text executable
MD5	ad1dc51a66201689d442499f70b78dea
SHA1	c71bccdc006cca700257a69ed227e0cb1bc071ed
SHA256	63788797919985d0e567cf9133ad2ab7a1c415e81598dc07c0bfa3a1566aeb90
SHA512	3258af057858ef0930a48771869871736bfb866ef740e81f2518c0d4c217b5c0c5f8eb06985b72a3762ce011458245940be6bb1d4907d2ed0f4e18886bbc48c3
ssdeep	12:HA4SKFBMygPZr7NBiC+c6jaY7PCbozFJG:thFBMZr7NBazjTzCbozG
Entropy	4.638131
Malware Result	unknown

Antivirus

No matches found.

YARA Rules

• rule CISA_10454006_11 : trojan
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10454006“
         date = „2023-07-20“
         last_modified = „20230726_1700“
         actor = „n/a“
         family = „n/a“
         Capabilities = „n/a“
         Malware_Type = „trojan“
         Tool_Type = „unknown“
         description = „Detects perl script linked to SKIPJACK backdoor samples“
         SHA256 = „63788797919985d0e567cf9133ad2ab7a1c415e81598dc07c0bfa3a1566aeb90“
     strings:
         $s1 = { 2f 65 74 63 2f 66 73 74 61 62 2e 6d 61 69 6e }
         $s2 = { 28 3c 46 53 54 41 42 3e 29 }
         $s3 = { 6d 79 20 28 24 70 61 72 74 69 74 69 6f 6e 2c 20 24 66 73 5f 74 79 70 65 29 }
         $s4 = { 70 72 69 6e 74 20 24 66 73 5f 74 79 70 65 }
         $s5 = { 70 72 69 6e 74 20 24 70 61 72 74 69 74 69 6f 6e }
     condition:
         all of them
  }

ssdeep Matches

No matches found.

Description

This artifact, belonging to the SKIPJACK malware family, is a Perl script that enumerates file system information. This script first checks the file system by opening ‚/etc/fstab.main/,‘ then checks the value against the array ‚ARGV[0]‘, which perl automatically provides to hold all values from the command line in. The script will print either ‚xfs‘ or hda depending on the type of file system it finds. The script contains a second if statement that gathers more information about the type of file system. This second if statement contains the regular expression ‚/^/dev/(S+)d+s+/s+(S+)/,‘ which translates to ‚/etc/fstab.‘ The script uses this second half of the code to check for file system type or information about the partition, which it then prints based on the value of ‚$requested_data.‘

Screenshots

 

44e1fbe71c9fcf9881230cb924987e0e615a7504c3c04d44ae157f07405e3598

Details

–>

Name	mod_sender.lua
Size	3930 bytes
Type	ASCII text
MD5	666da297066a2596cacb13b3da9572bf
SHA1	64b337d7e82c82a4b40c8cb88fbc651929995eef
SHA256	44e1fbe71c9fcf9881230cb924987e0e615a7504c3c04d44ae157f07405e3598
SHA512	4881a79d95bf83190be1542d7b26c7b1dee5eece1a689dc81bf2b661b43b3d724703dc4a48f824d8d960e2a480bcbea2e4007eb19023ee1bf329d993009deffc
ssdeep	96:JnJKszX3Z+p351GUw5FbsNmnwdx8sMEFoiKe3:JnJjzZ+j14FIEnqxjMEKQ
Entropy	5.041616
Malware Result	unknown

Antivirus

No matches found.

YARA Rules

• rule CISA_10454006_12 : SEASPRAY trojan evades_av
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10454006“
         date = „2023-08-23“
         last_modified = „20230905_1500“
         actor = „n/a“
         family = „SEASPRAY“
         capabilities = „evades-av“
         malware_type = „trojan“
         tool_type = „unknown“
         description = „Detects SEASPRAY samples“
         sha256 = „44e1fbe71c9fcf9881230cb924987e0e615a7504c3c04d44ae157f07405e3598“
     strings:
         $s1 = { 6f 73 2e 65 78 65 63 75 74 65 28 27 73 61 73 6c 61 75 74 63 68 64 27 }
         $s2 = { 73 65 6e 64 65 72 }
         $s3 = { 73 74 72 69 6e 67 2e 66 69 6e 64 }
         $s4 = { 73 74 72 69 6e 67 2e 6c 6f 77 65 72 }
         $s5 = { 62 6c 6f 63 6b 2f 61 63 63 65 70 74 }
         $s6 = { 72 65 74 75 72 6e 20 41 63 74 69 6f 6e 2e 6e 65 77 7b }
         $s7 = { 4c 69 73 74 65 6e 65 72 2e 6e 65 77 7b }
     condition:
         filesize < 10KB and all of them
  }

ssdeep Matches

No matches found.

Relationships

44e1fbe71c…

Used

9f04525835f998d454ed68cfc7fcb6b0907f2130ae6c6ab7495d41aa36ad8ccf

Description

This artifact is a trojanized Lua module that has been identified as a „SEASPRAY“ variant. SEASPRAY registers an event handler for all incoming email attachments. This variant checks for the sender and the string “obt”, which is hard coded in the lua file. If that string is found the malware uses os.execute to execute the file “saslautchd”, see Figure 3.

Screenshots

 

9f04525835f998d454ed68cfc7fcb6b0907f2130ae6c6ab7495d41aa36ad8ccf

Tags

trojan

Details

–>

Name	saslautchd
Size	5034648 bytes
Type	ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, BuildID[sha1]=913db6f2f3c21bcb11e0fd02e2b88908b15b5c2d, for GNU/Linux 3.2.0, stripped
MD5	436587bad5e061a7e594f9971d89c468
SHA1	cf22082532d4d6387ea1c9bc4dc5b255aa7a0290
SHA256	9f04525835f998d454ed68cfc7fcb6b0907f2130ae6c6ab7495d41aa36ad8ccf
SHA512	825ba4c46f1f9c5a4f2ab3ccfd8e3ec02f50f749776df783a085aff89cb19ed983b07ecd0703c74a0474bec56e918ada002b683dec1228f18181a91b0b339234
ssdeep	98304:J8sPi2iUKJYO0OAgikIn9FCJM+rXKZ9ldvVkhyfMuG9vU:xVUildN0uX
Entropy	6.384586
Malware Result	unknown

Antivirus

Antiy	Trojan/Linux.SAgnt
Avira	LINUX/Whirlpool.A
Bitdefender	Trojan.Generic.34035237
Emsisoft	Trojan.Generic.34035237 (B)
ESET	Linux/WhirlPool.A trojan
McAfee	Generic trojan.xj
Sophos	Linux/Agnt-BS
Varist	E64/Agent.FP

YARA Rules

• rule CISA_10452108_02 : WHIRLPOOL backdoor communicates_with_c2 installs_other_components
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10452108“
         date = „2023-06-20“
         last_modified = „20230804_1730“
         actor = „n/a“
         family = „WHIRLPOOL“
         Capabilities = „communicates-with-c2 installs-other-components“
         Malware_Type = „backdoor“
         Tool_Type = „unknown“
         description = „Detects malicious Linux WHIRLPOOL samples“
         sha256_1 = „83ca636253fd1eb898b244855838e2281f257bbe8ead428b69528fc50b60ae9c“
         sha256_2 = „8849a3273e0362c45b4928375d196714224ec22cb1d2df5d029bf57349860347“
     strings:
         $s0 = { 65 72 72 6f 72 20 2d 31 20 65 78 69 74 }
         $s1 = { 63 72 65 61 74 65 20 73 6f 63 6b 65 74 20 65 72 72 6f 72 3a 20 25 73 28 65 72 72 6f 72 3a 20 25 64 29 }
         $s2 = { c7 00 20 32 3e 26 66 c7 40 04 31 00 }
         $a3 = { 70 6c 61 69 6e 5f 63 6f 6e 6e 65 63 74 }
         $a4 = { 63 6f 6e 6e 65 63 74 20 65 72 72 6f 72 3a 20 25 73 28 65 72 72 6f 72 3a 20 25 64 29 }
         $a5 = { 73 73 6c 5f 63 6f 6e 6e 65 63 74 }
     condition:
         uint32(0) == 0x464c457f and 4 of them
  }

ssdeep Matches

No matches found.

Relationships

9f04525835…

Used_By

44e1fbe71c9fcf9881230cb924987e0e615a7504c3c04d44ae157f07405e3598

Description

This artifact, belonging to the WHIRLPOOL malware family, is a 64-bit Linux Executable and Linkable Format (ELF) file. The malware checks processor hardware and architecture, to include if the target system uses AMD or Intel, see Figure 4. Figure 5 shows the malware determining the kernel version by invoking the ‚uname‘ command line function and exploring the contents of the ‚/proc/sys/kernel/osrelease‘ file. Figures 6, 7, and 8 show the malware’s capacity to connect to a remote address, and then create a new process with the command line argument ‚/bin/sh.‘ The connection to a remote host and the invocation of a bash shell are the two components/phases used by reverse shells. Figure 9 shows the malware’s capacity to interact with the Name Service Cache Daemon by creating and connecting to a Unix socket at ./var/run/nscd/socket.‘ This socket can cache Domain Name System (DNS) requests. Rather than listening on port 53, it listens on the socket file itself, for data from other programs/processes. Figure 10 shows the malware’s capacity to perform DNS resolution, using the system call ’sys_getpeername.‘ The malware accesses the target’s environment variables. See below list below:

–Begin Accessed Environment Variables–
GCONV_PATH
GETCONF_DIR
HTTPS_PROXY
HTTP_PROXY
LANG
LANGUAGE
LC_ALL
LC_COLLATE
LD_WARN
LD_LIBRARY_PATH
LD_BIND_NOW
LD_BIND_NOT
LD_DYNAMIC_WEAK
LD_PROFILE_OUTPUT
LD_ASSUME_KERNEL
LOCALDOMAIN
NO_PROXY
OPENSSL_CONF
OPENSSL_ia32cap
OUTPUT_CHARSET
POSIX
TZ
TZDIR
RESOLV_ADD_TRIM_DOMAINS
RESOLV_HOST_CONF
RESOLV_MULTI
RESOLV_OVERRIDE_TRIM_DOMAINS
RES_OPTIONS
RESOLV_REORDER
–End Accessed Environment Variables–

The malware further access the following files at runtime:

–Begin Accessed Files–
/etc/aliases
/etc/ethers
/etc/group
/etc/hosts
/etc/networks
/etc/protocols
/etc/passwd
/etc/rpc
/etc/services
/etc/gshadow
/etc/shadow
/etc/netgroup
/dev/full
/dev/urandom
/dev/random
/proc/sys/kernel/rtsig-
/proc/sys/kernel/ngroups_max
/sys/devices/system/cpu/online
/proc/stat
/proc/self/fd
— End Accessed Files–

Screenshots

 

 

 

 

 

 

 

caab341a35badbc65046bd02efa9ad2fe2671eb80ece0f2fa9cf70f5d7f4bedc

Tags

trojan

Details

–>

Name	mod_rft.so
Size	1668232 bytes
Type	ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, stripped
MD5	4ec4ceda84c580054f191caa09916c68
SHA1	6505513ca06db10b17f6d4792c30a53733309231
SHA256	caab341a35badbc65046bd02efa9ad2fe2671eb80ece0f2fa9cf70f5d7f4bedc
SHA512	c61493cfa3c6c41520b6ef608da9398b4fa6a7805293bc98d628335f536509d95585d42f93b8edeabf971390e874c5291b552afe66d72651839a295b76c42380
ssdeep	24576:25gY/a9MQrLO457KIRTQvAunkEKkb8EHA4pje0ET1Nyb+YpYcNvwoQItHzUMDb:25b8y45V2IVEHASjezfYHwoDzUM
Entropy	6.211061
Malware Result	unknown

Antivirus

AhnLab	Malware/Linux.Agent
Antiy	Trojan/Linux.SaltWater.b
Bitdefender	Trojan.Linux.Generic.313776
Emsisoft	Trojan.Linux.Generic.313776 (B)
ESET	a variant of Linux/SaltWater.B trojan
McAfee	Generic trojan.xj
Quick Heal	ELF.WhirlPool.48041.GC
Sophos	Linux/Agnt-BS

YARA Rules

• rule CISA_10454006_13 : SALTWATER backdoor exploit_kit communicates_with_c2 determines_c2_server hides_executing_code exploitation
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10454006“
         date = „2023-08-10“
         last_modified = „20230905_1500“
         actor = „n/a“
         family = „SALTWATER“
         capabilities = „communicates-with-c2 determines-c2-server hides-executing-code“
         malware_type = „backdoor exploit-kit“
         tool_type = „exploitation“
         description = „Detects SALTWATER samples“
         sha256 = „caab341a35badbc65046bd02efa9ad2fe2671eb80ece0f2fa9cf70f5d7f4bedc“
     strings:
         $s1 = { 70 74 68 72 65 61 64 5f 63 72 65 61 74 65 }
         $s2 = { 67 65 74 68 6f 73 74 62 79 6e 61 6d 65 }
         $s3 = { 54 72 61 6d 70 6f 6c 69 6e 65 }
         $s4 = { 64 73 65 6c 64 73 }
         $s5 = { 25 30 38 78 20 28 25 30 32 64 29 20 25 2d 32 34 73 20 25 73 25 73 25 73 0a }
         $s6 = { 45 6e 74 65 72 20 6f 75 73 63 64 6f 6f 65 7c 70 72 65 64 61 72 65 28 25 70 2c 20 25 70 2c 20 25 70 29 }
         $s7 = { 45 6e 74 65 72 20 61 75 74 63 63 6f 6f 71 38 63 72 65 61 74 65 }
         $s8 = { 74 6e 6f 72 6f 74 65 63 74 6a 73 65 6d 6f 72 79 }
         $s9 = { 56 55 43 4f 4d 49 53 53 }
         $s10 = { 56 43 4f 4d 49 53 53 }
         $s11 = { 55 43 4f 4d 49 53 44 }
         $s12 = { 41 45 53 4b 45 59 47 45 4e 41 53 53 49 53 54 }
         $s13 = { 46 55 43 4f 4d 50 50 }
         $s14 = { 55 43 4f 4d 49 53 53 }
     condition:
         uint16(0) == 0x457f and filesize < 1800KB and 8 of them
  }

ssdeep Matches

No matches found.

Description

This artifact, belonging to the SALTWATER malware family, is a 32-bit Linux Shared Object (.so) file. The malware can intake data over the network, using a previously established socket, with the ‚recv‘ function as shown in Figure 11. Figure 12 shows the malware creating a new thread, within the calling process. This is thread injection and it can inject two different functions. Figure 13 shows the first function that can perform DNS resolution. Figures 14 and 15 show the second function. The second function can establish communications, over the network, using a TLS version 1 connection. Lastly, using ‚popen‘, the malware can execute any shell command with the same privileges as its calling process.

Screenshots

Relationship Summary

Recommendations

Contact Information

Document FAQ

Notification

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:CLEAR–Recipients may share this information without restriction. Sources may use TLP:CLEAR 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:CLEAR information may be shared without restriction. For more information on the Traffic Light Protocol (TLP), see http://www.cisa.gov/tlp.

Summary

Description

CISA received 4 files for analysis from an incident response engagement conducted at an Aeronautical Sector organization.

2 files (bitmap.exe, wkHPd.exe) are identified as variants of Metasploit (Meterpreter) and designed to connect and receive unencrypted payloads from their respective command and control (C2) servers. Note: Metasploit is an open source penetration testing software; Meterpreter is a Metasploit attack payload that runs an interactive shell. These executables are used as attack payloads to run interactive shells, allowing a malicious actor the ability to control and execute code on a system.

2 files (resource.aspx, ConfigLogin.aspx) are Active Server Pages (ASPX) web shells designed to execute remote JavaScript code on the victim server.

CISA has provided indicators of compromise (IOCs) and YARA rules for detection within this Malware Analysis Report (MAR).

For more information about this compromise, see Joint Cybersecurity Advisory Multiple Nation-State Threat Actors Exploit CVE-2022-47966 and CVE-2022-42475.

Download the PDF version of this report:

For a downloadable copy of IOCs associated with this MAR in JSON format, see:

Submitted Files (4)

334c2d0af191ed96b15095a4a098c400f2c0ce6b9c66d1800f6b74554d59ff4b (bitmap.exe)

47dacb8f0b157355a4fd59ccbac1c59b8268fe84f3b8a462378b064333920622 (resource.aspx)

6dcc7b5e913154abac69687fcfb6a58ac66ec9b8cc7de7afd8832a9066b7bdde (ConfigLogin.aspx)

79a9136eedbf8288ad7357ddaea3a3cd1a57b7c6f82adffd5a9540e1623bfb63 (wkHPd.exe)

IPs (2)

108[.]62[.]118[.]160

179[.]60[.]147[.]4

Findings

334c2d0af191ed96b15095a4a098c400f2c0ce6b9c66d1800f6b74554d59ff4b

Tags

downloaderobfuscatedtrojan

Details

–>

Antivirus

YARA Rules

• rule CISA_10430311_01 : METERPRETER trojan downloader
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10430311“
         date = „2023-03-03“
         last_modified = „20230404_1200“
         actor = „n/a“
         family = „METERPRETER“
         Capabilities = „n/a“
         Malware_Type = „trojan downloader“
         Tool_Type = „n/a“
         description = „Detects trojan downloader samples“
         sha256_1 = „334c2d0af191ed96b15095a4a098c400f2c0ce6b9c66d1800f6b74554d59ff4b“
     strings:
         $s1 = { 49 be 77 73 32 5f 33 32 }
         $s2 = { 49 89 e6 48 81 ec a0 01 }
         $s3 = { 49 bc 02 00 e5 6b b3 3c 93 04 }
         $s4 = { 41 ba 4c 77 26 07 ff d5 }
         $s5 = { 41 ba ea 0f df e0 ff d5 }
         $s6 = { 41 ba 99 a5 74 61 ff d5 }
         $s7 = { 41 ba 02 d9 c8 5f ff d5 }
         $s8 = { 41 ba 58 a4 53 e5 ff d5 }
     condition:
         all of them
  }
• rule CISA_10430311_02 : METERPRETER controls_local_machine compromises_data_integrity communicates_with_c2 keylogger exploit_kit remote_access_trojan back downloader screen_capture virus remote_access exploitation network_capture
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10430311“
         date = „2023-03-08“
         last_modified = „20230405_1300“
         actor = „n/a“
         family = „METERPRETER“
         Capabilities = „controls-local-machine compromises-data-integrity communicates-with-c2“
         Malware_Type = „keylogger exploit-kit remote-access-trojan backdoor downloader screen-capture virus“
         Tool_Type = „remote-access exploitation network-capture“
         description = „Detects Fresh Meterpreter bianary samples“
         sha256_1 = „79a9136eedbf8288ad7357ddaea3a3cd1a57b7c6f82adffd5a9540e1623bfb63“
         sha256_2 = „334c2d0af191ed96b15095a4a098c400f2c0ce6b9c66d1800f6b74554d59ff4b“
         sha256_3 = „6dcc7b5e913154abac69687fcfb6a58ac66ec9b8cc7de7afd8832a9066b7bdde“
         sha256_4 = „47dacb8f0b157355a4fd59ccbac1c59b8268fe84f3b8a462378b064333920622“
     strings:
         $s0 = { 58 a4 53 e5 }
         $s1 = { 02 d9 c8 5f }
         $s2 = { 99 a5 74 61 }
         $s3 = { 4c 77 26 07 }
         $s4 = { 29 80 6b 00 }
         $s5 = { 50 41 59 4c 4f 41 44 3a }
         $s6 = { 48 83 ec 28 49 c7 c1 40 }
     condition:
         all of them
  }

ssdeep Matches

No matches found.

Relationships

Description

This artifact is a malicious Windows executable file. The file is designed to connect to a remote Internet Protocol (IP) address „179[.]60[.]147[.]4“ on Transmission Control Protocol (TCP) port 58731 and waits for a response. The response payload from the remote server is not encrypted and will be executed in memory. The payload was not available for analysis.

179[.]60[.]147[.]4

Tags

command-and-control

Ports

• 58731 TCP

Whois

inetnum:     179.60.147.0/24
status:     reallocated
aut-num:     AS209588
owner:     Cloud Solutions S.A.
ownerid:     VE-CSSA1-LACNIC
responsible: Alexis Sanchez
address:     Av. Libertador, Distrito Capital, —,
address:     1050 – Caracas –
country:     VE
phone:     +507 8589115
owner-c:     ALS317
tech-c:     ALS317
abuse-c:     ALS317
inetrev:     179.60.147.0/24
nserver:     NS1.SAFE-VPN.MOBI
nsstat:     20230302 AA
nslastaa:    20230302
nserver:     NS2.SAFE-VPN.MOBI
nsstat:     20230302 AA
nslastaa:    20230302
created:     20220301
changed:     20220301
inetnum-up: 179.60.144.0/21

nic-hdl:     ALS317
person:     Alexis Sanchez
e-mail:     info@safe-vpn.mobi
address:     Av. Libertador, Distrito Capital, —, —
address:     1050 – Caracas –
country:     VE
phone:     +507 858 91 [15]
created:     20220301
changed:     20220301

Relationships

Description

The malware C2 server IP address.

79a9136eedbf8288ad7357ddaea3a3cd1a57b7c6f82adffd5a9540e1623bfb63

Tags

obfuscatedtrojan

Details

–>

Antivirus

YARA Rules

• rule CISA_10430311_02 : METERPRETER controls_local_machine compromises_data_integrity communicates_with_c2 keylogger exploit_kit remote_access_trojan back downloader screen_capture virus remote_access exploitation network_capture
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10430311“
         date = „2023-03-08“
         last_modified = „20230405_1300“
         actor = „n/a“
         family = „METERPRETER“
         Capabilities = „controls-local-machine compromises-data-integrity communicates-with-c2“
         Malware_Type = „keylogger exploit-kit remote-access-trojan backdoor downloader screen-capture virus“
         Tool_Type = „remote-access exploitation network-capture“
         description = „Detects Fresh Meterpreter bianary samples“
         sha256_1 = „79a9136eedbf8288ad7357ddaea3a3cd1a57b7c6f82adffd5a9540e1623bfb63“
         sha256_2 = „334c2d0af191ed96b15095a4a098c400f2c0ce6b9c66d1800f6b74554d59ff4b“
         sha256_3 = „6dcc7b5e913154abac69687fcfb6a58ac66ec9b8cc7de7afd8832a9066b7bdde“
         sha256_4 = „47dacb8f0b157355a4fd59ccbac1c59b8268fe84f3b8a462378b064333920622“
     strings:
         $s0 = { 58 a4 53 e5 }
         $s1 = { 02 d9 c8 5f }
         $s2 = { 99 a5 74 61 }
         $s3 = { 4c 77 26 07 }
         $s4 = { 29 80 6b 00 }
         $s5 = { 50 41 59 4c 4f 41 44 3a }
         $s6 = { 48 83 ec 28 49 c7 c1 40 }
     condition:
         all of them
  }

ssdeep Matches

No matches found.

Relationships

Description

This file is a malicious 64-bit Windows Portable Executable (PE) that has been identified as a variant of the Metasploit Meterpreter application. The file is designed to connect to a remote Internet Protocol (IP) address 108[.]62[.]118[.]160.

108[.]62[.]118[.]160

Tags

command-and-control

Whois

NetRange:     108.62.0.0 – 108.62.255.255
CIDR:         108.62.0.0/16
NetName:        NET-108-62-0-0-1
NetHandle:     NET-108-62-0-0-1
Parent:         NET108 (NET-108-0-0-0-0)
NetType:        Direct Allocation
OriginAS:     AS15003
Organization: Leaseweb USA, Inc. (LU)
RegDate:        2010-12-13
Updated:        2021-02-15
Ref:            https://rdap.arin.net/registry/ip/108.62.0.0

OrgName:        Leaseweb USA, Inc.
OrgId:         LU
Address:        9480 Innovation Dr
City:         Manassas
StateProv:     VA
PostalCode:     20109
Country:        US
RegDate:        2010-09-13
Updated:        2019-08-13
Comment:        www.leaseweb.com
Ref:            https://rdap.arin.net/registry/entity/LU

Relationships

Description

The malware attempts to connect to this IP address.

47dacb8f0b157355a4fd59ccbac1c59b8268fe84f3b8a462378b064333920622

Tags

backdoorwebshell

Details

–>

Antivirus

YARA Rules

• rule CISA_10430311_03 : ASPX_WEBSHELL webshell
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10430311“
         date = „2023-03-21“
         last_modified = „20230404_1230“
         actor = „n/a“
         family = „ASPX Webshell“
         Capabilities = „n/a“
         Malware_Type = „webshell“
         Tool_Type = „n/a“
         description = „Detects OWA targeting ASPX Webshell samples“
         sha256_1 = „6dcc7b5e913154abac69687fcfb6a58ac66ec9b8cc7de7afd8832a9066b7bdde“
         sha256_1 = „47dacb8f0b157355a4fd59ccbac1c59b8268fe84f3b8a462378b064333920622“
     strings:
         $s1 = { 5a 30 32 6a 77 36 43 36 63 55 }
         $s2 = { 5a 38 49 30 32 38 33 6e 77 38 }
         $s3 = { 4f 57 41 77 65 62 63 6f 6e 66 69 67 }
         $s4 = { 54 55 43 53 4f 4e }
         $s5 = { 65 76 61 6c }
     condition:
         3 of them
  }

ssdeep Matches

No matches found.

Description

This artifact is an ASPX webshell that is designed to execute remote JavaScript code on the system. The attacker must authenticate to the webshell client with the key „OWAwebconfig“ before executing the remote code. The ‚unsafe‘ context keyword is intentionally obfuscated to bypass security protocols.

Screenshots

6dcc7b5e913154abac69687fcfb6a58ac66ec9b8cc7de7afd8832a9066b7bdde

Tags

backdoorwebshell

Details

–>

Antivirus

YARA Rules

• rule CISA_10430311_03 : ASPX_WEBSHELL webshell
  {
     meta:
         author = „CISA Code & Media Analysis“
         incident = „10430311“
         date = „2023-03-21“
         last_modified = „20230404_1230“
         actor = „n/a“
         family = „ASPX Webshell“
         Capabilities = „n/a“
         Malware_Type = „webshell“
         Tool_Type = „n/a“
         description = „Detects OWA targeting ASPX Webshell samples“
         sha256_1 = „6dcc7b5e913154abac69687fcfb6a58ac66ec9b8cc7de7afd8832a9066b7bdde“
         sha256_1 = „47dacb8f0b157355a4fd59ccbac1c59b8268fe84f3b8a462378b064333920622“
     strings:
         $s1 = { 5a 30 32 6a 77 36 43 36 63 55 }
         $s2 = { 5a 38 49 30 32 38 33 6e 77 38 }
         $s3 = { 4f 57 41 77 65 62 63 6f 6e 66 69 67 }
         $s4 = { 54 55 43 53 4f 4e }
         $s5 = { 65 76 61 6c }
     condition:
         3 of them
  }

ssdeep Matches

No matches found.

Description

This artifact is an ASPX webshell that is designed to execute remote JavaScript code on the system. The attacker must authenticate to the webshell client with the key „TUCSON“ before executing the remote code. The ‚unsafe‘ context keyword is intentionally obfuscated to bypass security protocols.

Screenshots

Relationship Summary

Recommendations

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“.

Contact Information

• 1-844-Say-CISA
• 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://us-cert.cisa.gov/forms/feedback/

Document FAQ

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 1-844-Say-CISA 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.