Analysis

  • max time kernel
    91s
  • max time network
    139s
  • platform
    windows11-21h2_x64
  • resource
    win11-20240221-en
  • resource tags

    arch:x64arch:x86image:win11-20240221-enlocale:en-usos:windows11-21h2-x64system
  • submitted
    31/03/2024, 00:53

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:4928
    • 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:3636
    • 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:1720
      • 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:2372

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/1720-9-0x00007FFD53620000-0x00007FFD540E2000-memory.dmp

    Filesize

    10.8MB

  • memory/1720-10-0x000000001B890000-0x000000001B8A0000-memory.dmp

    Filesize

    64KB

  • memory/1720-11-0x000000001B830000-0x000000001B880000-memory.dmp

    Filesize

    320KB

  • memory/1720-12-0x000000001C050000-0x000000001C102000-memory.dmp

    Filesize

    712KB

  • memory/1720-15-0x000000001BFC0000-0x000000001BFD2000-memory.dmp

    Filesize

    72KB

  • memory/1720-16-0x000000001CB60000-0x000000001CB9C000-memory.dmp

    Filesize

    240KB

  • memory/1720-17-0x00007FFD53620000-0x00007FFD540E2000-memory.dmp

    Filesize

    10.8MB

  • memory/4928-0-0x0000000000230000-0x0000000000554000-memory.dmp

    Filesize

    3.1MB

  • memory/4928-1-0x00007FFD53620000-0x00007FFD540E2000-memory.dmp

    Filesize

    10.8MB

  • memory/4928-2-0x000000001B220000-0x000000001B230000-memory.dmp

    Filesize

    64KB

  • memory/4928-8-0x00007FFD53620000-0x00007FFD540E2000-memory.dmp

    Filesize

    10.8MB