Analysis

  • max time kernel
    142s
  • max time network
    151s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20231215-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20231215-enlocale:en-usos:windows10-2004-x64system
  • submitted
    10/02/2024, 18:48

General

  • Target
    Client-built.exe
  • Size 348KB
  • Sample240210-xf8rcsfc2v
  • SHA256 a764ab21f9c2d5f150e7a664f8e7e6f28089a8ef0aaf891fc1fb5aa5d4ebf9ce
  • MD5 SHA1 SHA512 SSDEEP

Malware Config

Extracted

Family
  • quasar

Version
  • 1.3.0.0

Botnet
  • Office04

C2
  • torbrowser-39837.portmap.host:39837

Mutex
  • QSR_MUTEX_mKtX4dxnsu2wSaZtko

Attributes
  • encryption_key

    thraD5vGF6dBOg1osqaQ

  • install_name

    Client.exe

  • log_directory

    Logs

  • reconnect_delay

    200

  • startup_key

    WindowsUserSupport

  • subdirectory

    SubDir

Signatures

  • Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 2 IoCs
  • Executes dropped EXE 1 IoCs
  • Looks up external IP address via web service 1 IoCs

    Uses a legitimate IP lookup service to find the infected system's external IP.

  • 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 9 IoCs

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:1636
    • C:\Windows\SysWOW64\schtasks.exe
      "schtasks" /create /tn "WindowsUserSupport" /sc ONLOGON /tr "C:\Users\Admin\AppData\Local\Temp\Client-built.exe" /rl HIGHEST /f
      2⤵
      • Creates scheduled task(s)
      PID:4340
    • C:\Users\Admin\AppData\Roaming\SubDir\Client.exe
      "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe"
      2⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      PID:4700
      • C:\Windows\SysWOW64\schtasks.exe
        "schtasks" /create /tn "WindowsUserSupport" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f
        3⤵
        • Creates scheduled task(s)
        PID:4848

Network

        MITRE ATT&CK Enterprise v15

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        Client.exe

        • Path C:\Users\Admin\AppData\Roaming\SubDir\Client.exe
        • Size 348KB
        • SHA256 a764ab21f9c2d5f150e7a664f8e7e6f28089a8ef0aaf891fc1fb5aa5d4ebf9ce
        • MD5 SHA1 SHA512 SSDEEP

        memory/1636-6-0x0000000005E20000-0x0000000005E32000-memory.dmp

        memory/1636-1-0x0000000000E20000-0x0000000000E7E000-memory.dmp

        memory/1636-3-0x00000000058A0000-0x0000000005932000-memory.dmp

        memory/1636-4-0x0000000005A10000-0x0000000005A20000-memory.dmp

        memory/1636-5-0x0000000005940000-0x00000000059A6000-memory.dmp

        memory/1636-0-0x0000000074A00000-0x00000000751B0000-memory.dmp

        memory/1636-7-0x0000000006E20000-0x0000000006E5C000-memory.dmp

        memory/1636-2-0x0000000005E50000-0x00000000063F4000-memory.dmp

        memory/1636-15-0x0000000074A00000-0x00000000751B0000-memory.dmp

        memory/4700-14-0x0000000074A00000-0x00000000751B0000-memory.dmp

        memory/4700-16-0x0000000004B30000-0x0000000004B40000-memory.dmp

        memory/4700-18-0x0000000006220000-0x000000000622A000-memory.dmp

        memory/4700-19-0x0000000074A00000-0x00000000751B0000-memory.dmp

        memory/4700-20-0x0000000004B30000-0x0000000004B40000-memory.dmp