Analysis

  • max time kernel
    149s
  • max time network
    151s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240412-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240412-enlocale:en-usos:windows10-2004-x64system
  • submitted
    15-04-2024 03:28

General

  • Target

    HEUR-Trojan.MSIL.Quasar.exe

  • Size

    3.4MB

  • MD5

    a585d666df5ca83eabcd06a4f0364523

  • SHA1

    4f5d8d09aaaf33efda276c3f7ab9883eda146da6

  • SHA256

    788c859458ab91850978e27a2591b564e5e3200eede844362bf465944db9d92c

  • SHA512

    4cd1aa6c0c15264cf00feed59552e6bd1ce663af54d5fe27ac193d8af77abd23522938166ec0318482dbee6c78a6cc97f1e75a1ea148390da7c2aee6a3bca544

  • SSDEEP

    49152:qvFt62XlaSFNWPjljiFa2RoUYIe5UU88DoGdWTHHB72eh2NTF:qv362XlaSFNWPjljiFXRoUYIIUU8E9

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

85.219.48.223:6969

Mutex

dd7993dd-3ead-48cf-ab1a-635718753276

Attributes
  • encryption_key

    DC9E2A3C163F32C37AC47FC14DF7F94F33786801

  • install_name

    Client.exe

  • log_directory

    Logs

  • reconnect_delay

    3000

  • startup_key

    :)

  • subdirectory

    SubDir

Signatures

  • Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 2 IoCs
  • Detects Windows executables referencing non-Windows User-Agents 2 IoCs
  • Detects binaries (Windows and macOS) referencing many web browsers. Observed in information stealers. 2 IoCs
  • Detects executables containing common artifacts observed in infostealers 2 IoCs
  • Executes dropped EXE 1 IoCs
  • Adds Run key to start application 2 TTPs 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 FindShellTrayWindow 1 IoCs
  • Suspicious use of SendNotifyMessage 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\HEUR-Trojan.MSIL.Quasar.exe
    "C:\Users\Admin\AppData\Local\Temp\HEUR-Trojan.MSIL.Quasar.exe"
    1⤵
    • Adds Run key to start application
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:2040
    • C:\Windows\SYSTEM32\schtasks.exe
      "schtasks" /create /tn ":)" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f
      2⤵
      • Creates scheduled task(s)
      PID:4780
    • C:\Users\Admin\AppData\Roaming\SubDir\Client.exe
      "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe"
      2⤵
      • Executes dropped EXE
      • Adds Run key to start application
      • Suspicious use of AdjustPrivilegeToken
      • Suspicious use of FindShellTrayWindow
      • Suspicious use of SendNotifyMessage
      • Suspicious use of WriteProcessMemory
      PID:2796
      • C:\Windows\SYSTEM32\schtasks.exe
        "schtasks" /create /tn ":)" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f
        3⤵
        • Creates scheduled task(s)
        PID:4196

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads

  • C:\Users\Admin\AppData\Roaming\SubDir\Client.exe

    Filesize

    3.4MB

    MD5

    a585d666df5ca83eabcd06a4f0364523

    SHA1

    4f5d8d09aaaf33efda276c3f7ab9883eda146da6

    SHA256

    788c859458ab91850978e27a2591b564e5e3200eede844362bf465944db9d92c

    SHA512

    4cd1aa6c0c15264cf00feed59552e6bd1ce663af54d5fe27ac193d8af77abd23522938166ec0318482dbee6c78a6cc97f1e75a1ea148390da7c2aee6a3bca544

  • memory/2040-0-0x0000000000FA0000-0x0000000001306000-memory.dmp

    Filesize

    3.4MB

  • memory/2040-1-0x00007FFFA1720000-0x00007FFFA21E1000-memory.dmp

    Filesize

    10.8MB

  • memory/2040-2-0x000000001C1C0000-0x000000001C1D0000-memory.dmp

    Filesize

    64KB

  • memory/2040-10-0x00007FFFA1720000-0x00007FFFA21E1000-memory.dmp

    Filesize

    10.8MB

  • memory/2796-9-0x00007FFFA1720000-0x00007FFFA21E1000-memory.dmp

    Filesize

    10.8MB

  • memory/2796-11-0x0000000002D50000-0x0000000002D60000-memory.dmp

    Filesize

    64KB

  • memory/2796-12-0x000000001B760000-0x000000001B7B0000-memory.dmp

    Filesize

    320KB

  • memory/2796-13-0x000000001BFB0000-0x000000001C062000-memory.dmp

    Filesize

    712KB

  • memory/2796-14-0x00007FFFA1720000-0x00007FFFA21E1000-memory.dmp

    Filesize

    10.8MB

  • memory/2796-15-0x0000000002D50000-0x0000000002D60000-memory.dmp

    Filesize

    64KB