Malware Analysis Report (AR20-045A)

MAR-10265965-1.v1 – North Korean Trojan: BISTROMATH

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: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.

Summary

Description

This Malware Analysis Report (MAR) is the result of analytic efforts between 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 Trojan malware variants used by the North Korean government. This malware variant has been identified as BISTROMATH. 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.

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 multiple versions of a full-featured RAT implant executable and multiple versions of the CAgent11 GUI implant controller/builder. These samples performs simple XOR network encoding and are capable of many features including conducting system surveys, file upload/download, process and command execution, and monitoring the microphone, clipboard, and the screen. The GUI controllers allow interaction with the implant as well as the option to dynamically build new implants with customized options. The implants are loaded with a trojanized executable containing a fake bitmap which decodes into shellcode which loads the embedded implant.

For a downloadable copy of IOCs, see MAR-101265965-1.v1.stix.

Submitted Files (5)

04d70bb249206a006f83db39bbe49ff6e520ea329e5fbb9c758d426b1c8dec30 (96071956D4890AEBEA14ECD8015617...)

1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39 (688890DDBF532A4DE7C83A58E6AA59...)

618a67048d0a9217317c1d1790ad5f6b044eaa58a433bd46ec2fb9f9ff563dc6 (0AE8A7B6B4D70C0884095629FC02C1...)

738ba44188a93de6b5ca7e0bf0a77f66f677a0dda2b2e9ef4b91b1c8257da790 (C51416635E529183CA5337FADE8275...)

b6811b42023524e691b517d19d0321f890f91f35ebbdf1c12cbb92cda5b6de32 (26520499A3FC627D335E34586E99DE...)

Additional Files (2)

133820ebac6e005737d5bb97a5db549490a9f210f4e95098bc9b0a7748f52d1f (a21171923ec09b9569f2baad496c9e...)

43193c4efa8689ff6de3fb18e30607bb941b43abb21e8cee0cfd664c6f4ad97c (83833f8dbdd6ecf3a1212f5d1fc3d9...)

IPs (1)

159.100.250.231

Findings

1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39

Tags

backdooremotettrojan

Details
Name 688890DDBF532A4DE7C83A58E6AA594F
Name ss.exe
Size 1102926 bytes
Type PE32 executable (GUI) Intel 80386, for MS Windows
MD5 688890ddbf532a4de7c83a58e6aa594f
SHA1 d8f6a7f32c929ce9458691447ff1cf6d180588c8
SHA256 1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39
SHA512 8484bea6adf27c2323632c3e94f91eb313e341622b5696b0d24105be1f24fa356f5fceb8fcf691e2d309fd24f7d8bb41fd7b682c29193128a0ed55e9ef3df3b1
ssdeep 24576:kgWxnOH3vvS+7nD03glQ1J6cS2lvyip5HkRpB7T4IRMh3y:kgWZMvSKnY3DJLSoORT7ThAC
Entropy 7.951069
Antivirus
Ahnlab Trojan/Win32.Bmdoor
Antiy Trojan[Backdoor]/Win32.Androm
Avira TR/Injector.ukfuc
BitDefender Trojan.GenericKD.41987827
ClamAV Win.Trojan.Agent-7376538-0
Cyren W32/Trojan.IZTF-2035
ESET a variant of Win32/Injector.DQTY trojan
Emsisoft Trojan.GenericKD.41987827 (B)
Ikarus Trojan.Win32.Injector
K7 Riskware ( 0040eff71 )
McAfee Trojan-Injector.c
Microsoft Security Essentials Trojan:Win32/Agentesla!MTB
NANOAV Trojan.Win32.Androm.ghyuau
Sophos Troj/Inject-ETF
Symantec Backdoor.Tidserv
Systweak trojan.injector
TACHYON Backdoor/W32.Androm.1102926
TrendMicro TROJ_FR.7170E263
TrendMicro House Call TROJ_FR.7170E263
VirusBlokAda Backdoor.Androm
Zillya! Backdoor.Androm.Win32.44606
YARA Rules
  • rule CryptographyFunction    
    {
       meta:
           author = "CISA trusted 3rd party"
           incident = "10271944.r1.v1"
           date =    "2019-12-25"
           category = "Hidden_Cobra"
           family = "HOTCROISSANT"
       strings:
           $ALGO_crypto_1 = { 8A [1-5] 32 [1-4] 32 [1-4] 32 [1-4] 88 [1-5] 8A [1-4] 32 [1-4] 22 [1-4] 8B [1-5] 8D [3-7] 33 [1-4] 81 [3-7] C1 [1-5] C1 [1-5] 0B [1-4] 8D [1-5] 33 [1-4] 22 [1-4] C1 [1-5] 33 [1-4] 32 [1-4] 8B [1-4] 83 [1-5] C1 [1-5] 33 [1-4] C1 [1-5] C1 }
       condition:
           uint16(0) == 0x5A4D and any of them
    }
ssdeep Matches

No matches found.

PE Metadata
Compile Date 2008-01-17 10:34:19-05:00
Import Hash 68d3c5fd0c41042f190fa12a4eebfe1b
PE Sections
MD5 Name Raw Size Entropy
0b8ab9af886c4161371944bd46af685d header 1024 2.484025
0cc984b88cda683bad52d886fbadf22d .text 77824 6.585222
d7200a9095f81e46d89eb2175a7d16ba .rdata 21504 4.940483
56eae295cdc645a889cc51643c19ca1c .data 5632 3.200450
31d4e62663767a64bd72b957df2bed2e .rsrc 1536 4.029623
c7a9818fe1b1f64be18f67db25dbed6d .reloc 7680 4.982554
Packers/Compilers/Cryptors
Microsoft Visual C++ ?.?
Relationships
1ea6b3e99b... Connected_To 159.100.250.231
1ea6b3e99b... Contains 43193c4efa8689ff6de3fb18e30607bb941b43abb21e8cee0cfd664c6f4ad97c
Description

The samples use a PlanetCPP.com ‘RichEdit example’ executable to obfuscate calling a decryption function which decrypts an embedded ‘fake’ bitmap image into the configuration and shellcode. When the malicious function is called, it deobfuscates API pointers, loads the full file into memory, calculates an offset into the memory to a ‘fake’ bitmap image, decodes the image; which becomes configuration options and shellcode and then executes the shellcode.

The embedded shellcode has many selectable options.

----------Begin Shellcode Options----------
- option00: Embedded vs Downloaded payload
   0 -> payload embedded within own file at offset (option27 + option28 + option22)
   1 -> Download payload from url <option30> to %temp$\<option31>\RGID3D88.tmp

- option01: True -> check for vm artifacts:
   registry checks:
       VMWARE Scsi device
       VBOX Scsi device
       QEMU Scsi device
       SOFTWARE\Vmware,Inc.\Vmware_Tools
       HARDWARE\Description\System\SystemBiosVersion == "VBOX"
       HARDWARE\Description\System\SystemBiosVersion == "QEMU"
       HARDWARE\Description\System\SystemBiosVersion == "BOCHS"
       HARDWARE\Description\System\VideoBiosVersion == "VIRTUALBOX"
       HARDWARE\Description\System\SystemBiosDate == 06/23/99
       SOFTWARE\Oracle\VirtualBox_Guest_Additions        
       HARDWARE\ACPI\DSDT\VBOX_
       HARDWARE\ACPI\FADT\VBOX__
       HARDWARE\ACPI\RSDT\VBOX__
       SYSTEM\ControlSet001\Services\VBoxGuest
       SYSTEM\ControlSet001\Services\VBoxMouse
       SYSTEM\ControlSet001\Services\VBoxService
       SYSTEM\ControlSet001\Services\VBoxSF
       SYSTEM\ControlSet001\Services\VBoxVideo
   file checks:
       C:\WINDOWS\system32\drivers\vmmouse.sys
       C:\WINDOWS\system32\drivers\vmhgfs.sys
       \\.\HGFS
       \\.\vmci
       C:\WINDOWS\system32\drivers\VBoxMouse.sys
       C:\WINDOWS\system32\drivers\VBoxGuest.sys
       C:\WINDOWS\system32\drivers\VBoxSF.sys
       C:\WINDOWS\system32\drivers\VBoxVideo.sys
       C:\WINDOWS\system32\vboxdisp.dll
       C:\WINDOWS\system32\vboxhook.dll
       C:\WINDOWS\system32\vboxmrxnp.dll
       C:\WINDOWS\system32\vboxogl.dll
       C:\WINDOWS\system32\vboxoglarrayspu.dll
       C:\WINDOWS\system32\vboxoglcrutil.dll
       C:\WINDOWS\system32\vboxoglerrorspu.dll
       C:\WINDOWS\system32\vboxoglfeedbackspu.dll
       C:\WINDOWS\system32\vboxoglpackspu.dll
       C:\WINDOWS\system32\vboxoglpassthroughspu.dll
       C:\WINDOWS\system32\vboxservice.exe
       C:\WINDOWS\system32\vboxtray.exe
       C:\WINDOWS\system32\VBoxControl.exe
       C:\program_files\oracle\virtualbox_guest_additions
       \\.\VBoxMiniRdrDN
       \\.\pipe\VBoxMiniRdDN
       \\.\VBoxTrayIPC
       \\.\pipe\VBoxTrayIPC        
   Network Adapter checks:
       Check for Vmware MAC addresses
       Check for VirtualBox MAC addresses
       Check for VMware network adapter
   Window Checks:
       VBoxTrayToolWndClass
       VBoxTrayToolWnd
   Process Checks:
       vboxservice.exe
       vboxtray.exe
   Loaded DLLs:
       vmcheck.dll

- option02: True -> check for sandbox artifacts:
   Verify spin loops aren't skipped
   Verify kernel32 doesn't contain export "wine_get_unix_file_name"
   Verify Numa api calls are not bypassed
   Loaded DLLs:
       SbieDll.dll
       api_log.dll
       dir_watch.dll
       dbghelp.dll
       wpespy.dll
   registry checks:
       SOFTWARE\Wine
   file checks:
       C:\sandbox\sandbox.exe    
       C:\sandbox\sbfwe.dll    
   username checks:
       SANDBOX
       VIRUS
       MALWARE
       SCHMIDTI
       CURRENTUSER
       ANDY
   current directory checks:
       VIRUS
       SANDBOX
       SAMPLE

- option03: True -> check for debugging artifacts:    
   API calls:
       IsDebuggerPresent
       CheckRemoteDebuggerPresent
       NtQueryInformationProcess
       GetThreadContext
       OutputDebugString

- option04: Check if certain processes are running:
   0 -> ignored
   1 -> exit if specific processes are running
   2 -> exit if specific processes are not running
   parses option31_array_+0x200 for a list of ;,: separated process names

- option05: Queries Software\Microsoft\Windows\CurrentVersion\Uninstall keys
   exits if return value is != 0

- option06: Check for specific languages
   0 -> ignored
   1 -> exit if current language is found in list
   2 -> exit if current language is not found in list
   parses option31_array_+0x4b0 for a list of ;,: separated languages

- option07: Check for specific usernames
   0 -> ignored
   1 -> exit if current username is found in list
   2 -> exit if current username is not found in list
   parses option31_array_+0x6b8 for a list of ;,: separated usernames

- option08: Check for specific computernames
   0 -> ignored
   1 -> exit if current computernames is found in list
   2 -> exit if current computernames is not found in list
   parses option31_array_+0x8ac for a list of ;,: separated computernames

- option09: Something with querying Software\Microsoft\Windows\CurrentVersion\Uninstall keys
   exits if return value is < option09_value

- option10: integer value -> exits if there are fewer than this many processes running

- option11-14: Check for system/drive info
   11==0x001 -> exit if number of processors <= option12
   11==0x010 -> exit if total physical memory <= option13
   11==0x100 -> exit if total harddisk space <= option14

- option12/27/28: if True -> exploit dll hijack in cliconfg.exe (SQL Server Client Network Utility)
   dumps a number (option28) of bytes from an offset (option27) of this file into %temp%\ntwdblib.dll
   creates a Software\Claiomh registry key
   executes cliconfg.exe (which loads ntwdblib.dll)

- option16: Set EnableLUA registry key
   SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA to <option16>

- option17: Create Persistence
   0 -> ignored
   1 -> Add registry key to Software\Microsoft\Windows\CurrentVersion\Run using a name from option31_array_+0x960
   2 -> Copy self into Startup folder
   3 -> Create an hourly Scheduled Task called "System Backup"

- option18/23: Process Hollowing vs Drop/Execute
   == 0 -> Do Process Hollowing
   != 0 -> Dump payload to file and execute directly:
       write to %temp%\RT5380.exe using own file offset (option27 + option28 + option22) and execute
       write to %temp%\<option30> using own file offset (option27 + option28 + option22) and execute
       check option23:
- ==0 -> ignored
- !=0 -> delete self and replace self with the dropped file

- option19: Process to create/hollow/inject/execute
   0 -> self
   1 -> svchost.exe
   2 -> conhost.exe
   3 -> explorer.exe
   4 -> value of "http\shell\open\command" registry key
   5 -> <option33>

- option20: Sleep timer
   Milliseconds to sleep before doing process hollowing

- option21/26: Kill timer
   0 -> ignored
   1 -> if timestamp of module + <option26> >= currentTime -> remove persistance, delete self, exit process

- option29/34/35: move file to desired location, delete old file, and execute from new location
   additional path is in option34
   new filename is in option35
   0 -> C:\
   1 -> %windir%
   2 -> %system%
   3 -> %programfiles%
   4 -> %programfiles%\Common Files\
   5 -> C:\ProgramData\
   6 -> %userprofile%
   7 -> %userprofile%\Documents\
   8 -> %temp%
   9 -> %userprofile%\Favorites\
   10 -> %appdata%n
   11 -> %localappdata%

- option36: char[40] - Unknown - Possibly adds a mutex to the hollowed process to enforce a single execution
   Uses argument to create a named mutex
   Injects additional code into the hollowed process (from offset 0x28c0)
   Injects <option36> into the hollowed process
   Creates another remote thread in the hollowed process pointing at offset 0x465a of the newly injected memory
----------End Shellcode Options----------

Screenshots
Figure 1: Implant Functionality -

Figure 1: Implant Functionality -

618a67048d0a9217317c1d1790ad5f6b044eaa58a433bd46ec2fb9f9ff563dc6

Tags

dropperemotetkeyloggerspywaretrojan

Details
Name 0AE8A7B6B4D70C0884095629FC02C19C
Name CAgent11.exe
Size 13498368 bytes
Type PE32 executable (GUI) Intel 80386, for MS Windows
MD5 0ae8a7b6b4d70c0884095629fc02c19c
SHA1 9efa2d68932ff24cb18eb7e35aa5f91ce99596e8
SHA256 618a67048d0a9217317c1d1790ad5f6b044eaa58a433bd46ec2fb9f9ff563dc6
SHA512 08f724812cbeff4020ac3fb07cafec5cde17f53f4644d554351cf4056907a6363d5b21ed3720976820307b43a543e81c6cc27c241f4449fd92aae6ad58b75995
ssdeep 196608:Klq/1ui17DaLU1l4O5dm/+f99FLOyomFHKnPG:GcvlmLMg/299F
Entropy 5.658332
Antivirus
Ahnlab Dropper/Win32.Keylogger
Antiy Trojan[Spy]/Win32.Agent
Avira HEUR/AGEN.1038092
Cyren W32/Agent.RBBJ-4429
ESET a variant of Win32/Spy.Agent.PUH trojan
Ikarus Trojan-Spy.Agent
K7 Spyware ( 00555d821 )
McAfee Trojan-Injector.d
Microsoft Security Essentials Trojan:Win32/Emotet
NANOAV Trojan.Win32.Graftor.ggzicq
NetGate Trojan.Win32.Malware
Sophos Troj/Agent-BCXS
Symantec Trojan Horse
Systweak malware.keylogger
TACHYON Trojan/W32.Keylogger.13498368
VirusBlokAda TrojanSpy.Agent
Zillya! Trojan.Agent.Win32.1169060
YARA Rules

No matches found.

ssdeep Matches

No matches found.

PE Metadata
Compile Date 2017-03-21 21:12:17-04:00
Import Hash c4406c66f7ca84ffb881d843c49acbd6
PE Sections
MD5 Name Raw Size Entropy
e7e02cd4a189cea5efaa8fb36509aa45 header 1024 3.530105
d41d8cd98f00b204e9800998ecf8427e .textbss 0 0.000000
5db50cefbb12a73d10aad429548befe7 .text 7047680 5.565086
e9a63040b7f3e75b5746d8202d8594f5 .rdata 904704 4.415613
1e815bbe0c5cadf4953bbaac6259dcaa .data 40448 4.299279
16342b710a408579ee34f3ccf9927331 .idata 28672 5.161732
c573bd7cea296a9c5d230ca6b5aee1a6 .tls 1024 0.011174
011d6c8672f924dc710a68acb6bc74f9 .00cfg 512 0.061163
867de3faa85f377519582ed29a83384c .rsrc 5123072 4.951562
e74f13482e13eb316d544b69a046ff15 .reloc 351232 6.011950
Packers/Compilers/Cryptors
Microsoft Visual C++ 8.0
Description

See analysis for "04D70BB249206A006F83DB39BBE49FF6E520EA329E5FBB9C758D426B1C8DEC30".

Implants built with sample "04D70BB249206A006F83DB39BBE49FF6E520EA329E5FBB9C758D426B1C8DEC30" are not compatible with this controller, and vice versa.

b6811b42023524e691b517d19d0321f890f91f35ebbdf1c12cbb92cda5b6de32

Tags

backdooremotettrojan

Details
Name 26520499A3FC627D335E34586E99DE7A
Name ADManager.exe
Size 1120318 bytes
Type PE32 executable (GUI) Intel 80386, for MS Windows
MD5 26520499a3fc627d335e34586e99de7a
SHA1 df10c097e42dbe7ea4478a984c5e2ab586147519
SHA256 b6811b42023524e691b517d19d0321f890f91f35ebbdf1c12cbb92cda5b6de32
SHA512 898ab1a1cd5a731e94a7b4c0a274e81092fe6de2ea888b3db2d22cf4d0bacbbb36f486152ff10f61f054091aee421f00d89a8741fce0f370cc14d80a62f77bc3
ssdeep 24576:3gWPfTO4H59Z6PTvnh2gf2JfvoioZ74XKBpNCY+SOToKMcxGa52w:3gW3S4Z9ATcggox4wpwYq9Mcx3B
Entropy 7.953591
Antivirus
Ahnlab Backdoor/Win32.Androm
Antiy Trojan[Backdoor]/Win32.Androm
Avira TR/Injector.cskrn
BitDefender Trojan.GenericKD.41987802
ClamAV Win.Trojan.Agent-7376533-0
Cyren W32/Androm.DKHG-0510
ESET a variant of Win32/Injector.DQTY trojan
Emsisoft Trojan.GenericKD.41987802 (B)
Ikarus Trojan.Win32.Injector
K7 Riskware ( 0040eff71 )
McAfee Trojan-Injector.c
Microsoft Security Essentials Trojan:Win32/Agentesla!MTB
NANOAV Trojan.Win32.Androm.ggadbc
Sophos Troj/Inject-ETF
Symantec Trojan Horse
Systweak trojan.injector
TACHYON Backdoor/W32.Androm.1120318
TrendMicro TROJ_FR.7170E263
TrendMicro House Call TROJ_FR.7170E263
VirusBlokAda Backdoor.Androm
Zillya! Backdoor.Androm.Win32.44606
YARA Rules
  • rule CryptographyFunction    
    {
       meta:
           author = "CISA trusted 3rd party"
           incident = "10271944.r1.v1"
           date =    "2019-12-25"
           category = "Hidden_Cobra"
           family = "HOTCROISSANT"
       strings:
           $ALGO_crypto_1 = { 8A [1-5] 32 [1-4] 32 [1-4] 32 [1-4] 88 [1-5] 8A [1-4] 32 [1-4] 22 [1-4] 8B [1-5] 8D [3-7] 33 [1-4] 81 [3-7] C1 [1-5] C1 [1-5] 0B [1-4] 8D [1-5] 33 [1-4] 22 [1-4] C1 [1-5] 33 [1-4] 32 [1-4] 8B [1-4] 83 [1-5] C1 [1-5] 33 [1-4] C1 [1-5] C1 }
       condition:
           uint16(0) == 0x5A4D and any of them
    }
ssdeep Matches

No matches found.

PE Metadata
Compile Date 2017-03-26 09:21:10-04:00
Import Hash 68d3c5fd0c41042f190fa12a4eebfe1b
PE Sections
MD5 Name Raw Size Entropy
a507172c7e89d3f88c70c4fd6827a522 header 1024 2.476553
0cc984b88cda683bad52d886fbadf22d .text 77824 6.585222
d7200a9095f81e46d89eb2175a7d16ba .rdata 21504 4.940483
56eae295cdc645a889cc51643c19ca1c .data 5632 3.200450
58dbdc33cb7f42b5e3a9f0fcc94d6b1f .rsrc 1024 4.796047
c7a9818fe1b1f64be18f67db25dbed6d .reloc 7680 4.982554
Packers/Compilers/Cryptors
Microsoft Visual C++ ?.?
Relationships
b6811b4202... Connected_To 159.100.250.231
b6811b4202... Contains 133820ebac6e005737d5bb97a5db549490a9f210f4e95098bc9b0a7748f52d1f
Description

See analysis for file "1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39" for additional details.

738ba44188a93de6b5ca7e0bf0a77f66f677a0dda2b2e9ef4b91b1c8257da790

Tags

trojan

Details
Name C51416635E529183CA5337FADE82758A
Name server.exe
Size 947200 bytes
Type PE32 executable (GUI) Intel 80386, for MS Windows
MD5 c51416635e529183ca5337fade82758a
SHA1 830368d88b661d09c084e484713effb8d230d328
SHA256 738ba44188a93de6b5ca7e0bf0a77f66f677a0dda2b2e9ef4b91b1c8257da790
SHA512 244b67e0b9e9ab2fa6ccceeb4ad71207f1d8371af9c69af93bcc15cc8b592aca54e9c241d439b94ed28923d4622050fccdc38b326a8d15b824301cf0aae46cb0
ssdeep 24576:9oV9SPwODditnxk93QKTrCEgqAGYOEgJZ+0Mn:9o2I2du23QxErv7ESZ+7n
Entropy 6.703705
Antivirus
Ahnlab Malware/Win32.Generic
Antiy Trojan/Win32.AGeneric
Avira HEUR/AGEN.1038092
BitDefender Trojan.GenericKD.32683846
ClamAV Win.Trojan.Agent-7376468-0
Cyren W32/Agent.KUBI-8127
ESET a variant of Win32/Agent.SSC trojan
Emsisoft Trojan.GenericKD.32683846 (B)
Ikarus Trojan.Win32.Agent
K7 Trojan ( 0027657e1 )
McAfee Generic Trojan.sh
NANOAV Trojan.Win32.TrjGen.ghyubn
Sophos Troj/Agent-BCXS
Symantec Trojan Horse
Systweak malware.passwordstealer
TrendMicro TROJ_FR.7170E263
TrendMicro House Call TROJ_FR.7170E263
VirusBlokAda BScope.TrojanSpy.Agent
Zillya! Trojan.Agent.Win32.1168332
YARA Rules

No matches found.

ssdeep Matches

No matches found.

PE Metadata
Compile Date 2017-04-13 23:44:03-04:00
Import Hash d31e404296b957729148721e11f3bc88
PE Sections
MD5 Name Raw Size Entropy
1db5d7f5d8e2fa35f4077d3c28b60ae7 header 1024 3.229935
6f6469c660281de2c72fa3685d55a8ec .text 710656 6.655052
0847400b5430782ad644a30cd8240c73 .rdata 167424 5.776485
77ab2f92d6177b9e39430447aa595073 .data 37376 5.315603
1f354d76203061bfdd5a53dae48d5435 .tls 512 0.020393
1704ffd93e9d463dc42784bc03bbfd5d .gfids 512 2.779799
850aa99c8c1a85dc7545811d66bb0c17 .rsrc 512 4.717679
48da542e50cc8e12bdb9cab38a8ce0cb .reloc 29184 6.576636
Packers/Compilers/Cryptors
Microsoft Visual C++ ?.?
Relationships
738ba44188... Connected_To 159.100.250.231
Description

This sample is a full-featured RAT executable.

See analysis for file "1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39" for additional details. This sample varies slightly in the following ways.

Victim_info for this version contains Unicode strings. The RAT is controllable by an unknown variant of CAgent.exe.

04d70bb249206a006f83db39bbe49ff6e520ea329e5fbb9c758d426b1c8dec30

Tags

dropperemotetkeyloggerspywaretrojan

Details
Name 96071956D4890AEBEA14ECD8015617CC
Name CAgent11.exe
Size 7014400 bytes
Type PE32 executable (GUI) Intel 80386, for MS Windows
MD5 96071956d4890aebea14ecd8015617cc
SHA1 49e16180795034a4888fff776968e29871f79340
SHA256 04d70bb249206a006f83db39bbe49ff6e520ea329e5fbb9c758d426b1c8dec30
SHA512 29abd5fa0c24e42916631f830b6860027dcefdfd320978bee389e55f4f04278668ec4cfb67e5b1c8b7133338cc0fb09ffae28c5cf6d5226d1f9e44381db17c41
ssdeep 98304:SC6l4uHxECiYwS2BsszjfisjJiBg1pDClmMFLOAkGkzdnEVomFHKnP:P44uHi0mFi+1p+FLOyomFHKnP
Entropy 5.907837
Antivirus
Ahnlab Dropper/Win32.Keylogger
Avira HEUR/AGEN.1038092
BitDefender Trojan.GenericKD.32683845
Cyren W32/Trojan.KVTC-7019
ESET a variant of Win32/Spy.Agent.PUH trojan
Emsisoft Trojan.GenericKD.32683845 (B)
Ikarus Trojan-Spy.Agent
K7 Spyware ( 00555d821 )
McAfee Trojan-Injector.d
Microsoft Security Essentials Trojan:Win32/Emotet
NANOAV Trojan.Win32.TrjGen.ghyuap
Sophos Troj/Agent-BCXS
Symantec Trojan Horse
Systweak malware.keylogger
TACHYON Trojan/W32.Keylogger.7014400
TrendMicro TROJ_FR.7170E263
TrendMicro House Call TROJ_FR.7170E263
VirusBlokAda TrojanSpy.Agent
Zillya! Trojan.Agent.Win32.1168788
YARA Rules

No matches found.

ssdeep Matches

No matches found.

PE Metadata
Compile Date 2017-03-26 00:28:24-04:00
Import Hash 0937a296014c778f116e3990f06e314b
PE Sections
MD5 Name Raw Size Entropy
a9fb26d3d4f4a80f2c2f7aeb1201325a header 1024 3.391911
c788578d4f02ac011ffabd20db4506f3 .text 1619456 6.522579
7a1b03c4f7501d6f82d34a01fe9cf6b7 .rdata 348160 5.245418
50c4f4eab880975227b9b4d454941979 .data 24064 4.732755
b9af73df5ec7fb7a68b1c00d83e6b404 .gfids 111104 4.230152
52f93ebec3bc0c9da8e85ddf5ad812f4 .giats 512 0.155178
1f354d76203061bfdd5a53dae48d5435 .tls 512 0.020393
e0376d74c0a0f746949b4647d35ef424 .rsrc 4774400 5.470347
9011be24e5ab8066360bd7d0af07cea6 .reloc 135168 6.491093
Packers/Compilers/Cryptors
Microsoft Visual C++ ?.?
Description

This sample is a GUI implant controller titled “Cyber Agent v11.0”. It is capable of dynamically building new bot payloads with the following options:

--------Begin Payload Options----------
Callback IP
Callback Port
Beacon Interval
Output Path
--------End Payload Options----------

victim_info (see analysis for "43193c4efa8689ff6de3fb18e30607bb941b43abb21e8cee0cfd664c6f4ad97c") is displayed for each implant beacon received. The controller can establish Remote Desktop viewer, drive enumeration, file upload/download, list processes and services, reverse shell, microphone capture and recording, keylogger, browser activity, cached passwords, and DLL loading and unloading. The controller has the ability to provide implants with an Update URL as well as an option to uninstall all bots.

159.100.250.231

Ports
  • 80 TCP
  • 8080 TCP
Whois

% IANA WHOIS server
% for more information on IANA, visit http://www.iana.org
% This query returned 1 object

refer:        whois.arin.net

inetnum:     159.0.0.0 - 159.255.255.255
organisation: Administered by ARIN
status:     LEGACY

whois:        whois.arin.net

changed:     1993-05
source:     IANA

# whois.arin.net

NetRange:     159.100.0.0 - 159.101.255.255
CIDR:         159.100.0.0/15
NetName:        RIPE-ERX-159-100-0-0
NetHandle:     NET-159-100-0-0-1
Parent:         NET159 (NET-159-0-0-0-0)
NetType:        Early Registrations, Transferred to RIPE NCC
OriginAS:    
Organization: RIPE Network Coordination Centre (RIPE)
RegDate:        2003-10-29
Updated:        2003-10-29
Comment:        These addresses have been further assigned to users in
Comment:        the RIPE NCC region. Contact information can be found in
Comment:        the RIPE database at http://www.ripe.net/whois
Ref:            https://rdap.arin.net/registry/ip/159.100.0.0

ResourceLink: https://apps.db.ripe.net/search/query.html
ResourceLink: whois.ripe.net


OrgName:        RIPE Network Coordination Centre
OrgId:         RIPE
Address:        P.O. Box 10096
City:         Amsterdam
StateProv:    
PostalCode:     1001EB
Country:        NL
RegDate:        
Updated:        2013-07-29
Ref:            https://rdap.arin.net/registry/entity/RIPE

ReferralServer: whois://whois.ripe.net
ResourceLink: https://apps.db.ripe.net/search/query.html

OrgTechHandle: RNO29-ARIN
OrgTechName: RIPE NCC Operations
OrgTechPhone: +31 20 535 4444
OrgTechEmail: hostmaster@ripe.net
OrgTechRef:    https://rdap.arin.net/registry/entity/RNO29-ARIN

OrgAbuseHandle: ABUSE3850-ARIN
OrgAbuseName: Abuse Contact
OrgAbusePhone: +31205354444
OrgAbuseEmail: abuse@ripe.net
OrgAbuseRef:    https://rdap.arin.net/registry/entity/ABUSE3850-ARIN


# whois.ripe.net

inetnum:        159.100.245.0 - 159.100.255.255
netname:        Akenes
descr:         Exoscale Open Cloud DK2
descr:         Exoscale cloud hosting https://www.exoscale.ch
descr:         *******************************************************
descr:         * These IPs are customer assigned STATIC IPs.
descr:         * In case of abuse, please do NOT block entire
descr:         * network as IPs of this block are assigned as /32
descr:         * to individual customers.
descr:         *******************************************************
descr:         * For abuse-complaints please use
descr:         * only abuse@exoscale.ch.
descr:         *******************************************************
country:        CH
admin-c:        AC22866-RIPE
tech-c:         LLL1007-RIPE
status:         LEGACY
mnt-by:         Exoscale-MNT
created:        2017-11-20T10:37:49Z
last-modified: 2017-11-20T10:37:49Z
source:         RIPE

person:         Antoine COETSIER
address:        Boulevard de Grancy 19A
address:        1006 Lausanne
address:        SWITZERLAND
phone:         +41 58 255 00 66
nic-hdl:        AC22866-RIPE
mnt-by:         Exoscale-MNT
created:        2013-02-08T14:10:06Z
last-modified: 2019-04-11T05:30:08Z
source:         RIPE # Filtered

person:         Loic Lambiel
address:        Boulevard de Grancy 19A
address:        1006 Lausanne
address:        Switzerland
phone:         +41 58 255 00 66
nic-hdl:        LLL1007-RIPE
mnt-by:         Exoscale-MNT
created:        2013-02-15T10:16:52Z
last-modified: 2019-04-11T05:31:04Z
source:         RIPE # Filtered

% Information related to '159.100.248.0/21AS61098'

route:         159.100.248.0/21
origin:         AS61098
mnt-by:         Exoscale-MNT
created:        2016-12-14T10:12:52Z
last-modified: 2016-12-14T10:12:52Z
source:         RIPE

% This query was served by the RIPE Database Query Service version 1.95.1 (WAGYU)

Relationships
159.100.250.231 Connected_From 1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39
159.100.250.231 Connected_From b6811b42023524e691b517d19d0321f890f91f35ebbdf1c12cbb92cda5b6de32
159.100.250.231 Connected_From 738ba44188a93de6b5ca7e0bf0a77f66f677a0dda2b2e9ef4b91b1c8257da790
159.100.250.231 Connected_From 43193c4efa8689ff6de3fb18e30607bb941b43abb21e8cee0cfd664c6f4ad97c
Description

Hard-coded C2 address used by these RATs.

43193c4efa8689ff6de3fb18e30607bb941b43abb21e8cee0cfd664c6f4ad97c

Tags

keyloggerspywaretrojan

Details
Name 83833f8dbdd6ecf3a1212f5d1fc3d9dd
Size 905216 bytes
Type PE32 executable (GUI) Intel 80386, for MS Windows
MD5 83833f8dbdd6ecf3a1212f5d1fc3d9dd
SHA1 77a2272633eb64e4c16f8ea4466dba59ecc92292
SHA256 43193c4efa8689ff6de3fb18e30607bb941b43abb21e8cee0cfd664c6f4ad97c
SHA512 cda12a75b1d6524fe8856d6ef359ab58785e2c56ca4fec613b851a6730d24b8141dfdd00fba62f2865b8cc4606e85b258c02d71ccd45fcde769514eea88b23ff
ssdeep 24576:AECw5N98knVurfj9gbYX91XdKo1ldrtD9:AECwz9fqfj59NwuldrF
Entropy 6.710436
Antivirus
Ahnlab Trojan/Win32.KeyLogger
Antiy Trojan/Win32.AGeneric
Avira HEUR/AGEN.1038092
BitDefender Gen:Variant.Graftor.679285
ClamAV Win.Trojan.Agent-7376468-0
ESET a variant of Win32/Spy.Agent.PUH trojan
Emsisoft Gen:Variant.Graftor.679285 (B)
Ikarus Trojan-Spy.Agent
K7 Spyware ( 00555d821 )
NANOAV Trojan.Win32.Graftor.ggzicq
Sophos Troj/Agent-BCXS
Symantec Heur.AdvML.B
VirusBlokAda BScope.TrojanSpy.Agent
Zillya! Trojan.Agent.Win32.1170395
YARA Rules

No matches found.

ssdeep Matches

No matches found.

PE Metadata
Compile Date 2008-01-17 10:34:19-05:00
Import Hash 3b7df90688bca84764a888c49f25e8b9
PE Sections
MD5 Name Raw Size Entropy
064a795c4019629fd03c3d47c823cd49 header 1024 3.330520
ec60b9f4b78b0f79ea9d15910baf3d8d .text 672768 6.660080
3dd902a53e33d4f6b014f6a677620252 .rdata 164864 5.832569
0c88a9a99d1c3cb1b61009a6acb2539e .data 37376 5.304517
1f354d76203061bfdd5a53dae48d5435 .tls 512 0.020393
d5ea2a2452a9733e2cc63487e98b387d .gfids 512 2.821174
f42c4819230ff4b40b0e52850c134b08 .rsrc 512 4.708237
a1862d52a23162d56421552f09f1ca85 .reloc 27648 6.587842
Packers/Compilers/Cryptors
Microsoft Visual C++ ?.?
Relationships
43193c4efa... Contained_Within 1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39
43193c4efa... Connected_To 159.100.250.231
Description

This sample is a full-featured RAT executable contained within "1EA6B3E99BBB67719C56AD07F5A12501855068A4A866F92DB8DCDEFAFFA48A39".

See Figure 1 for full list of commands a hardcoded C2 address of 159.100.250.231 on port 8080 is contained within the sample. The RAT is controllable by CAgent.exe variant "618A67048D0A9217317C1D1790AD5F6B044EAA58A433BD46EC2FB9F9FF563DC6".

The Imports are obfuscated by prepending "CARAT_" to the API names.

Packets are formatted in the following format:

----------Begin Packet Formatting---------
[OPCODE] [4 Bytes length of data] [data]
----------Begin Packet Formatting---------

Packets are encoded by performing an XOR on the data after the header with the XOR key 0x07. The implant initiates callback to C2, then immediately sends its victim_info.

----------Begin Victim_Info----------
•    Language
•    Country
•    Victim_ID
•    Computer_Name
•    User_Name
•    Implant_Version = "11.0"
•    Victim_IP
•    System_Architecture
•    Drive_Letters
•    OS_Version
----------End Victim_Info----------

133820ebac6e005737d5bb97a5db549490a9f210f4e95098bc9b0a7748f52d1f

Tags

trojan

Details
Name a21171923ec09b9569f2baad496c9e16
Size 922624 bytes
Type PE32 executable (GUI) Intel 80386, for MS Windows
MD5 a21171923ec09b9569f2baad496c9e16
SHA1 35ba8e39e6c8234ad55baf27130bb696179b7681
SHA256 133820ebac6e005737d5bb97a5db549490a9f210f4e95098bc9b0a7748f52d1f
SHA512 c1775b68b6b083323780150f6da654c6bcaf313b298fd243047402a0d0ec5631f8c90ed7ccc28ff4c1eaf2666e671b9c0f6bc068ca9e0655740834b31fa62bd9
ssdeep 12288:KsukuhRC+VmUmEViUUwsaXpx3U09S5j4J6dxLqm1JaSjyQiEyDlZk7SxTmgaA6i:pukuhRC+Vr24v3qhdDaSuQCBZk7SUAB
Entropy 6.678910
Antivirus
Ahnlab Malware/Win32.Generic
Antiy Trojan/Win32.AGeneric
Avira HEUR/AGEN.1038092
ClamAV Win.Trojan.Agent-7376468-0
ESET a variant of Win32/Agent.SSC trojan
Symantec Heur.AdvML.B
YARA Rules

No matches found.

ssdeep Matches

No matches found.

PE Metadata
Compile Date 2017-03-26 09:21:10-04:00
Import Hash 80e9b5b96cb30be08b9f46dcd40ca0b6
PE Sections
MD5 Name Raw Size Entropy
480ee7622ef011b56ad9be1f520b53bb header 1024 3.124211
e0689d923085269b1433eb46c62b9aad .text 698880 6.634137
e1d4d4f7c07cb01481a7f937c1a399c5 .rdata 154112 5.641674
5b25e16d6a60901096dd38e8d609656f .data 38912 5.185811
1f354d76203061bfdd5a53dae48d5435 .tls 512 0.020393
4dd9e4bd9bce353817d7013e17254399 .rsrc 512 4.717679
6c01df76342b581365053b6550340347 .reloc 28672 6.610094
Packers/Compilers/Cryptors
Microsoft Visual C++ ?.?
Relationships
133820ebac... Contained_Within b6811b42023524e691b517d19d0321f890f91f35ebbdf1c12cbb92cda5b6de32
Description

This sample is a full-featured RAT executable contained within "B6811B42023524E691B517D19D0321F890F91F35EBBDF1C12CBB92CDA5B6DE32".

See analysis for file "1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39" for additional details. This sample varies slightly in the following ways.

----------Begin Packet Formatting---------
[OPCODE][4 Bytes data length][4 Bytes unused][AUTH CODE 72 50 BF 9E][Data]
----------End Packet Formatting---------

The implant initiates callback to C2, then waits for tasking (DOES NOT immediately send its victim_info) and the Victim_info for this version contains Unicode strings, it additionally adds UserGeoID to victim_info.

The sample attempts to connect to 159.100.250.231:8080 4 times, with 1 minute between attempts. If does not succeed, then attempts to connect to www.example.com 4 times, with 1 minute between attempts. This loop continues until a connection is made.

Relationship Summary

1ea6b3e99b... Connected_To 159.100.250.231
1ea6b3e99b... Contains 43193c4efa8689ff6de3fb18e30607bb941b43abb21e8cee0cfd664c6f4ad97c
b6811b4202... Connected_To 159.100.250.231
b6811b4202... Contains 133820ebac6e005737d5bb97a5db549490a9f210f4e95098bc9b0a7748f52d1f
738ba44188... Connected_To 159.100.250.231
159.100.250.231 Connected_From 1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39
159.100.250.231 Connected_From b6811b42023524e691b517d19d0321f890f91f35ebbdf1c12cbb92cda5b6de32
159.100.250.231 Connected_From 738ba44188a93de6b5ca7e0bf0a77f66f677a0dda2b2e9ef4b91b1c8257da790
159.100.250.231 Connected_From 43193c4efa8689ff6de3fb18e30607bb941b43abb21e8cee0cfd664c6f4ad97c
43193c4efa... Contained_Within 1ea6b3e99bbb67719c56ad07f5a12501855068a4a866f92db8dcdefaffa48a39
43193c4efa... Connected_To 159.100.250.231
133820ebac... Contained_Within b6811b42023524e691b517d19d0321f890f91f35ebbdf1c12cbb92cda5b6de32

Mitigation

Displayed below is a Python3 script used to decrypt and extract the embedded files:

--Begin Decryption and Extraction Python3 Script--
import argparse
import struct

def truncate_nullterm_str(data):
   null_index = data.find(b'\x00')
   truncated_str = data[:null_index].decode('utf-8')
   return truncated_str

def decode(offset,buffer,length,key1,key2):
   dec = b''
   k3 = key1
   key1 = key1 >> 1
   while length > 0:
       k1 = key1
       k2 = key2
       dec += bytes([(buffer[offset] ^ k1 ^ k2 ^ k3) & 0xff])
       key1 = (key1 >> 8 | ((key1 * 8 ^ key1) & 0x7f8) << 0x14) & 0xffffffff
       k3 = (k3 & k2 ^ (k2 ^ k3) & k1)
       key2 = (key2 >> 8 | (((key2 * 2 ^ key2) << 4 ^ key2) & 0xffffff80 ^ key2 << 7) << 0x11) & 0xffffffff
       offset += 1
       length -= 1
   return dec

offset = 0
def parse_options(buffer):
   options = list(struct.unpack('I'*30, buffer[0:120]))
   options.append(buffer[120:320])
   options.append(buffer[320:2820])
   options.append(buffer[2820:3020])
   options.append(buffer[3020:3120])
   options.append(buffer[3120:3220])
   options.append(buffer[3220:3320])
   options.append(buffer[3320:3360])

   enabled_options = ''
   disabled_options = ''

   if options[0] == 0:
       global offset
       offset = options[27] + options[28] + options[22]
       enabled_options += "Embedded payload at offset: %d\n" % offset
       disabled_options += "Download payload\n"
   else:
       enabled_options += "Download payload from: %s\n" % truncate_nullterm_str(options[30])
       disabled_options += "Embedded payload\n"

   str = "VM Detect\n"
   if options[1] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Sandbox Detect\n"
   if options[2] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Debugger Detect\n"
   if options[3] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Active Processes Check\n"
   if options[4] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Installed programs Check\n"
   if options[5] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Language Check\n"
   if options[6] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Username Check\n"
   if options[7] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Computer name Check\n"
   if options[8] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Installed number of programs Check\n"
   if options[9] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Number running processes Check\n"
   if options[10] == 0:
       disabled_options += str
   else:
       enabled_options += "Number running processes Check: %d\n" % options[10]

   str = "System processors/memory/diskspace Check\n"
   if options[11] == 0:
       disabled_options += str
   else:
       if options[11] & 0x001:
           enabled_options += "Processor count check: %d\n" % options[12]
       if options[11] & 0x010:
           enabled_options += "Physical memory check: %d\n" % options[13]
       if options[11] & 0x000:
           enabled_options += "Disk space check: %d\n" % options[14]

   str = "DLL Hijack cliconfg.exe\n"
   if options[12] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "EnableLUA\n"
   if options[16] == 0:
       disabled_options += str
   else:
       enabled_options += str

   str = "Create Persistence\n"
   if options[17] == 0:
       disabled_options += str
   elif options[17] == 1:
       enabled_options += "Create Persistence using Run key: %s\n" % truncate_nullterm_str(options[31][0x960:])
   elif options[17] == 2:
       enabled_options += "Create Persistence in Startup folder\n"
   elif options[17] == 3:
       enabled_options += "Create Persistence using \"System Backup\" hourly Scheduled Task\n"

   if options[18] == 0:
       disabled_options += "Direct Execution\n"
   else:
       disabled_options += "Process Hollowing\n"

   if options[19] == 0:
       enabled_options += "Process Hollowing: self\n"
   elif options[19] == 1:
       enabled_options += "Process Hollowing: svchost.exe\n"
   elif options[19] == 2:
       enabled_options += "Process Hollowing: conhost.exe\n"
   elif options[19] == 3:
       enabled_options += "Process Hollowing: explorer.exe\n"
   elif options[19] == 4:
       enabled_options += "Process Hollowing: \"http\shell\open\command\" registry key value\n"
   elif options[19] == 5:
       enabled_options += "Process Hollowing: %s\n" % truncate_nullterm_str(options[33])

   str = "Sleep Timer\n"
   if options[20] == 0:
       disabled_options += str
   else:
       enabled_options += "Sleep Timer: %d\n" % options[20]

   str = "Kill Timer\n"
   if options[21] == 0:
       disabled_options += str
   else:
       enabled_options += "Kill Timer: %d\n" % options[26]

   if options[29] == 0:
       enabled_options += "Relocate to: C:\\"
   elif options[29] == 1:
       enabled_options += "Relocate to: %windir%\\"
   elif options[29] == 2:
       enabled_options += "Relocate to: %system%\\"
   elif options[29] == 3:
       enabled_options += "Relocate to: %programfiles%\\"
   elif options[29] == 4:
       enabled_options += "Relocate to: %programfiles%\\Common Files\\"
   elif options[29] == 5:
       enabled_options += "Relocate to: C:\\ProgramData\\"
   elif options[29] == 6:
       enabled_options += "Relocate to: %userprofile%\\"
   elif options[29] == 7:
       enabled_options += "Relocate to: %userprofile%\\Documents\\"
   elif options[29] == 8:
       enabled_options += "Relocate to: %temp%\\"
   elif options[29] == 9:
       enabled_options += "Relocate to: %userprofile%\\Favorites\\"
   elif options[29] == 10:
       enabled_options += "Relocate to: %appdata%\\"
   elif options[29] == 11:
       enabled_options += "Relocate to: %localappdata%\\"
   if len(truncate_nullterm_str(options[34])) > 0:
       enabled_options += "%s\\" % truncate_nullterm_str(options[34])
   enabled_options += "%s\n" % truncate_nullterm_str(options[35])

   str = "Mutex\n"
   if len(truncate_nullterm_str(options[36])) == 0:
       disabled_options += str
   else:
       enabled_options += "Mutex: %s\n" % truncate_nullterm_str(options[36])

   print("\nDisabled Options:")
   print(disabled_options)

   print("\nEnabled Options:")
   print(enabled_options)


def main():
   parser = argparse.ArgumentParser()
   parser.add_argument('filename')
   args = parser.parse_args()

   with open(args.filename, 'rb') as f:
       exe = f.read()
       PE_header_pos = struct.unpack('<i', exe[0x3c:0x3c+4])[0]
       PE_header_len = struct.unpack('<i', exe[PE_header_pos+0x54:PE_header_pos+0x54+4])[0]
       PE_header_length = struct.unpack('<h', exe[PE_header_pos+0x14:PE_header_pos+0x14+2])[0]
       section_headers_pos = PE_header_pos + PE_header_length + 0x18
       num_headers = struct.unpack('<h', exe[PE_header_pos+0x6:PE_header_pos+0x6+2])[0]
       curr_header_pos = section_headers_pos
       bitmap_pos = PE_header_len
       for i in range(num_headers):
           header_len = struct.unpack('<i', exe[curr_header_pos+0x10:curr_header_pos+0x10+4])[0]
           bitmap_pos += header_len
           curr_header_pos += 0x28
       key1 = struct.unpack('<I', exe[bitmap_pos+0x3a:bitmap_pos+0x3a+4])[0]
       bitmap_len = len(exe) - bitmap_pos
       bitmap_header_len = struct.unpack('<H', exe[bitmap_pos+0x3e:bitmap_pos+0x3e+2])[0]
       key2 = struct.unpack('<I', exe[bitmap_pos+0x36:bitmap_pos+0x36+4])[0]
       bitmap_len -= bitmap_header_len
       bitmap_len -= 0x036
       print("[ ] Decoding %d Bytes with:" % bitmap_len)
       print("    Key1: %s" % hex(key1))
       print("    Key2: %s" % hex(key2))
       dec = decode(0,exe[bitmap_pos+bitmap_header_len+0x36:],bitmap_len,key1,key2)
       print("[+] Decoding Complete!")
       parse_options(dec[0:0xd56-0x36])
       payload_pos = 0xd56-0x36+offset
       print("[ ] Found embedded payload, extracting..")
       with open(args.filename + "_payload.exe", 'wb') as out:
           out.write(dec[payload_pos:])
       print("[+] Wrote %d Bytes to %s" % (len(dec[payload_pos:]), args.filename + "_payload.exe"))

if __name__ == '__main__':
   main()
--End Decryption and Extraction Python3 Script--

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

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.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 1-888-282-0870 or soc@us-cert.gov.

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

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.us-cert.gov.

Revisions

February 14, 2020: Initial Version

This product is provided subject to this Notification and this Privacy & Use policy.

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