Analysis

  • max time kernel
    151s
  • max time network
    111s
  • platform
    windows10_x64
  • resource
    win10v20210408
  • submitted
    29-09-2021 08:06

General

  • Target

    f20bcc23430a216c14e45207e84ca8cd819049af8d427e6a3ab38255c1fa8dda.exe

  • Size

    756KB

  • MD5

    50b53927892abfe41b08d0c6311c1a39

  • SHA1

    b43e1fec005c39a1a0b1ab31616522906fe4ba84

  • SHA256

    f20bcc23430a216c14e45207e84ca8cd819049af8d427e6a3ab38255c1fa8dda

  • SHA512

    e980a91d6a91f5a20eebf0a7ba7f7e2d1fe5748f73309cd2695bceb0b92b84208667e9c842a01d0606b76c4831cae3be2e13502d7ed80ff5b910f9ec3a4b41f4

Malware Config

Extracted

Family

darkcomet

Botnet

Guest16

C2

127.0.0.1:1604

Mutex

DC_MUTEX-0UX76EM

Attributes
  • InstallPath

    explorer\explorer.exe

  • gencode

    oxFTG57Sq0Jl

  • install

    true

  • offline_keylogger

    true

  • persistence

    true

  • reg_key

    MicroUpdate

Signatures

  • Darkcomet

    DarkComet is a remote access trojan (RAT) developed by Jean-Pierre Lesueur.

  • Modifies WinLogon for persistence 2 TTPs 1 IoCs
  • Modifies firewall policy service 2 TTPs 3 IoCs
  • Modifies security service 2 TTPs 1 IoCs
  • Windows security bypass 2 TTPs
  • Disables RegEdit via registry modification
  • Disables Task Manager via registry modification
  • Executes dropped EXE 1 IoCs
  • Sets file to hidden 1 TTPs

    Modifies file attributes to stop it showing in Explorer etc.

  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Deletes itself 1 IoCs
  • Windows security modification 2 TTPs 2 IoCs
  • Adds Run key to start application 2 TTPs 2 IoCs
  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

  • Modifies registry class 1 IoCs
  • Suspicious behavior: GetForegroundWindowSpam 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 48 IoCs
  • Suspicious use of SetWindowsHookEx 1 IoCs
  • Suspicious use of WriteProcessMemory 54 IoCs
  • System policy modification 1 TTPs 3 IoCs
  • Views/modifies file attributes 1 TTPs 2 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\f20bcc23430a216c14e45207e84ca8cd819049af8d427e6a3ab38255c1fa8dda.exe
    "C:\Users\Admin\AppData\Local\Temp\f20bcc23430a216c14e45207e84ca8cd819049af8d427e6a3ab38255c1fa8dda.exe"
    1⤵
    • Modifies WinLogon for persistence
    • Checks computer location settings
    • Adds Run key to start application
    • Modifies registry class
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:652
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /k attrib "C:\Users\Admin\AppData\Local\Temp\f20bcc23430a216c14e45207e84ca8cd819049af8d427e6a3ab38255c1fa8dda.exe" +s +h
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:1164
      • C:\Windows\SysWOW64\attrib.exe
        attrib "C:\Users\Admin\AppData\Local\Temp\f20bcc23430a216c14e45207e84ca8cd819049af8d427e6a3ab38255c1fa8dda.exe" +s +h
        3⤵
        • Views/modifies file attributes
        PID:696
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /k attrib "C:\Users\Admin\AppData\Local\Temp" +s +h
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:508
      • C:\Windows\SysWOW64\attrib.exe
        attrib "C:\Users\Admin\AppData\Local\Temp" +s +h
        3⤵
        • Views/modifies file attributes
        PID:960
    • C:\Windows\SysWOW64\notepad.exe
      notepad
      2⤵
      • Deletes itself
      PID:3992
    • C:\Users\Admin\Documents\explorer\explorer.exe
      "C:\Users\Admin\Documents\explorer\explorer.exe"
      2⤵
      • Modifies firewall policy service
      • Modifies security service
      • Executes dropped EXE
      • Windows security modification
      • Adds Run key to start application
      • Suspicious behavior: GetForegroundWindowSpam
      • Suspicious use of AdjustPrivilegeToken
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      • System policy modification
      PID:1728
      • C:\Windows\SysWOW64\notepad.exe
        notepad
        3⤵
          PID:3004

    Network

    MITRE ATT&CK Matrix ATT&CK v6

    Persistence

    Winlogon Helper DLL

    1
    T1004

    Modify Existing Service

    2
    T1031

    Hidden Files and Directories

    2
    T1158

    Registry Run Keys / Startup Folder

    1
    T1060

    Defense Evasion

    Modify Registry

    7
    T1112

    Disabling Security Tools

    2
    T1089

    Hidden Files and Directories

    2
    T1158

    Discovery

    Query Registry

    1
    T1012

    System Information Discovery

    2
    T1082

    Replay Monitor

    Loading Replay Monitor...

    Downloads

    • C:\Users\Admin\Documents\explorer\explorer.exe
      MD5

      50b53927892abfe41b08d0c6311c1a39

      SHA1

      b43e1fec005c39a1a0b1ab31616522906fe4ba84

      SHA256

      f20bcc23430a216c14e45207e84ca8cd819049af8d427e6a3ab38255c1fa8dda

      SHA512

      e980a91d6a91f5a20eebf0a7ba7f7e2d1fe5748f73309cd2695bceb0b92b84208667e9c842a01d0606b76c4831cae3be2e13502d7ed80ff5b910f9ec3a4b41f4

    • C:\Users\Admin\Documents\explorer\explorer.exe
      MD5

      50b53927892abfe41b08d0c6311c1a39

      SHA1

      b43e1fec005c39a1a0b1ab31616522906fe4ba84

      SHA256

      f20bcc23430a216c14e45207e84ca8cd819049af8d427e6a3ab38255c1fa8dda

      SHA512

      e980a91d6a91f5a20eebf0a7ba7f7e2d1fe5748f73309cd2695bceb0b92b84208667e9c842a01d0606b76c4831cae3be2e13502d7ed80ff5b910f9ec3a4b41f4

    • memory/508-116-0x0000000000000000-mapping.dmp
    • memory/652-114-0x0000000002230000-0x0000000002231000-memory.dmp
      Filesize

      4KB

    • memory/696-118-0x0000000000000000-mapping.dmp
    • memory/960-119-0x0000000000000000-mapping.dmp
    • memory/1164-115-0x0000000000000000-mapping.dmp
    • memory/1728-125-0x0000000002110000-0x0000000002111000-memory.dmp
      Filesize

      4KB

    • memory/1728-121-0x0000000000000000-mapping.dmp
    • memory/3004-126-0x0000000000650000-0x0000000000651000-memory.dmp
      Filesize

      4KB

    • memory/3004-124-0x0000000000000000-mapping.dmp
    • memory/3992-117-0x0000000000000000-mapping.dmp
    • memory/3992-120-0x0000000002E20000-0x0000000002E21000-memory.dmp
      Filesize

      4KB