Analysis

  • max time kernel
    1710s
  • max time network
    1790s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240226-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240226-enlocale:en-usos:windows10-2004-x64system
  • submitted
    31/03/2024, 00:42

General

  • Target

    Client-built.exe

  • Size

    3.1MB

  • MD5

    57045c2bf3377b12aa5abce21cc0a99d

  • SHA1

    217202ed404f25fc550ad70fd7066b0fe8773ef9

  • SHA256

    f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2

  • SHA512

    9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e

  • SSDEEP

    49152:Wv+I22SsaNYfdPBldt698dBcjHukuQPoGdhEQTHHB72eh2NT:Wvz22SsaNYfdPBldt6+dBcjHukuE

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Ratted

C2

140.238.91.110:44867

Mutex

be049c71-d631-4f68-8b3e-8e01081f2340

Attributes
  • encryption_key

    AA883CE7347A3543F81EBCDE3BBF3BFC9C60344E

  • install_name

    WOS64UPD.exe

  • log_directory

    Windows Update Logs

  • reconnect_delay

    3000

  • startup_key

    Windows Updater

  • subdirectory

    Windows

Signatures

  • Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 2 IoCs
  • Executes dropped EXE 1 IoCs
  • Creates scheduled task(s) 1 TTPs 2 IoCs

    Schtasks is often used by malware for persistence or to perform post-infection execution.

  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of SetWindowsHookEx 1 IoCs
  • Suspicious use of WriteProcessMemory 6 IoCs
  • Uses Task Scheduler COM API 1 TTPs

    The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.

Processes

  • C:\Users\Admin\AppData\Local\Temp\Client-built.exe
    "C:\Users\Admin\AppData\Local\Temp\Client-built.exe"
    1⤵
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:4208
    • C:\Windows\SYSTEM32\schtasks.exe
      "schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f
      2⤵
      • Creates scheduled task(s)
      PID:3200
    • C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
      "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe"
      2⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      PID:1668
      • C:\Windows\SYSTEM32\schtasks.exe
        "schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f
        3⤵
        • Creates scheduled task(s)
        PID:4404

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads

  • C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe

    Filesize

    3.1MB

    MD5

    57045c2bf3377b12aa5abce21cc0a99d

    SHA1

    217202ed404f25fc550ad70fd7066b0fe8773ef9

    SHA256

    f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2

    SHA512

    9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e

  • memory/1668-10-0x000000001B7E0000-0x000000001B7F0000-memory.dmp

    Filesize

    64KB

  • memory/1668-9-0x00007FFBAE1F0000-0x00007FFBAECB1000-memory.dmp

    Filesize

    10.8MB

  • memory/1668-11-0x0000000002DB0000-0x0000000002E00000-memory.dmp

    Filesize

    320KB

  • memory/1668-12-0x000000001C050000-0x000000001C102000-memory.dmp

    Filesize

    712KB

  • memory/1668-15-0x000000001B860000-0x000000001B872000-memory.dmp

    Filesize

    72KB

  • memory/1668-16-0x000000001BFD0000-0x000000001C00C000-memory.dmp

    Filesize

    240KB

  • memory/1668-17-0x00007FFBAE1F0000-0x00007FFBAECB1000-memory.dmp

    Filesize

    10.8MB

  • memory/1668-18-0x000000001B7E0000-0x000000001B7F0000-memory.dmp

    Filesize

    64KB

  • memory/4208-2-0x000000001BB70000-0x000000001BB80000-memory.dmp

    Filesize

    64KB

  • memory/4208-1-0x00007FFBAE1F0000-0x00007FFBAECB1000-memory.dmp

    Filesize

    10.8MB

  • memory/4208-8-0x00007FFBAE1F0000-0x00007FFBAECB1000-memory.dmp

    Filesize

    10.8MB

  • memory/4208-0-0x0000000000B30000-0x0000000000E54000-memory.dmp

    Filesize

    3.1MB