Resubmissions

19-04-2024 22:32

240419-2f4jvsab4t 10

19-04-2024 22:30

240419-2e2c4saa91 10

Analysis

  • max time kernel
    125s
  • max time network
    145s
  • platform
    windows11-21h2_x64
  • resource
    win11-20240412-en
  • resource tags

    arch:x64arch:x86image:win11-20240412-enlocale:en-usos:windows11-21h2-x64system
  • submitted
    19-04-2024 22:32

General

  • Target

    Client-built.exe

  • Size

    3.1MB

  • MD5

    491d53dcfb36c12d0077bbb926f24d02

  • SHA1

    4e35320259495d99e3d9fbc03aeea39c93c3a051

  • SHA256

    97cd6ad3a56efc266ba1860e2d1c5958094b988be74bd36e9499d22fdaed9c59

  • SHA512

    7f9a8134032cb437278422d7f0ea123e68146fc5f6f3de693592b96620669eb36696625235fddbebae0949e9ddbbd4d8f694c61f16489a38322d90149f70553b

  • SSDEEP

    49152:KvYt62XlaSFNWPjljiFa2RoUYIJkRJ6hbR3LoGdvTHHB72eh2NT:Kv062XlaSFNWPjljiFXRoUYIJkRJ6D

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

192.168.1.139:4782

Mutex

e12e9d8f-f86f-4c20-aaa9-ca4ae3df9435

Attributes
  • encryption_key

    8A5C503C69142D8C1F9A30FB7AA52FB2729B3861

  • install_name

    Client.exe

  • log_directory

    Logs

  • reconnect_delay

    3000

  • startup_key

    Client Startup

  • subdirectory

    SubDir

Signatures

  • Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 2 IoCs
  • Executes dropped EXE 1 IoCs
  • Drops file in System32 directory 2 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⤵
    • Drops file in System32 directory
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:2056
    • C:\Windows\SYSTEM32\schtasks.exe
      "schtasks" /create /tn "Client Startup" /sc ONLOGON /tr "C:\Windows\system32\SubDir\Client.exe" /rl HIGHEST /f
      2⤵
      • Creates scheduled task(s)
      PID:4300
    • C:\Windows\system32\SubDir\Client.exe
      "C:\Windows\system32\SubDir\Client.exe"
      2⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      PID:3944
      • C:\Windows\SYSTEM32\schtasks.exe
        "schtasks" /create /tn "Client Startup" /sc ONLOGON /tr "C:\Windows\system32\SubDir\Client.exe" /rl HIGHEST /f
        3⤵
        • Creates scheduled task(s)
        PID:2016

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads

  • C:\Windows\System32\SubDir\Client.exe

    Filesize

    3.1MB

    MD5

    491d53dcfb36c12d0077bbb926f24d02

    SHA1

    4e35320259495d99e3d9fbc03aeea39c93c3a051

    SHA256

    97cd6ad3a56efc266ba1860e2d1c5958094b988be74bd36e9499d22fdaed9c59

    SHA512

    7f9a8134032cb437278422d7f0ea123e68146fc5f6f3de693592b96620669eb36696625235fddbebae0949e9ddbbd4d8f694c61f16489a38322d90149f70553b

  • memory/2056-0-0x0000000000710000-0x0000000000A34000-memory.dmp

    Filesize

    3.1MB

  • memory/2056-1-0x00007FF93BA50000-0x00007FF93C512000-memory.dmp

    Filesize

    10.8MB

  • memory/2056-2-0x000000001B6D0000-0x000000001B6E0000-memory.dmp

    Filesize

    64KB

  • memory/2056-8-0x00007FF93BA50000-0x00007FF93C512000-memory.dmp

    Filesize

    10.8MB

  • memory/3944-9-0x00007FF93BA50000-0x00007FF93C512000-memory.dmp

    Filesize

    10.8MB

  • memory/3944-10-0x000000001BB70000-0x000000001BB80000-memory.dmp

    Filesize

    64KB

  • memory/3944-11-0x000000001BAE0000-0x000000001BB30000-memory.dmp

    Filesize

    320KB

  • memory/3944-12-0x000000001C4B0000-0x000000001C562000-memory.dmp

    Filesize

    712KB

  • memory/3944-13-0x00007FF93BA50000-0x00007FF93C512000-memory.dmp

    Filesize

    10.8MB