Analysis

  • max time kernel
    115s
  • max time network
    120s
  • platform
    windows11-21h2_x64
  • resource
    win11-20240419-en
  • resource tags

    arch:x64arch:x86image:win11-20240419-enlocale:en-usos:windows11-21h2-x64system
  • submitted
    15-05-2024 17:34

General

  • Target

    client.exe

  • Size

    3.1MB

  • MD5

    4a603ec4e3c5a21400eaabac7c6401c6

  • SHA1

    23b446721eacd0b6796407ca20bd1e01355ab41f

  • SHA256

    566ba756b7fc2174fc195c05d9e0a36aa706e4ce397f890488227b7d0ad4ad7c

  • SHA512

    070a5dd14bce16ba58eb65f3b3143fc7890f0e34f2ed7f3a1930e3fa8454ebcf615b43c819f16f4fc494676443bd409a3a57e8fe6e8f39ab02df5ace497eaea0

  • SSDEEP

    49152:rvrI22SsaNYfdPBldt698dBcjHLCc1J2LoGdcTHHB72eh2NT:rvU22SsaNYfdPBldt6+dBcjHLCn

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

79.132.193.215:4782

Mutex

f99ccef5-65c4-4972-adf2-fb38921cc9fc

Attributes
  • encryption_key

    1C15E91ACCFAC60B043A1336CF6912EA8572BA83

  • install_name

    Client.exe

  • log_directory

    Logs

  • reconnect_delay

    3000

  • startup_key

    Quasar Client Startup

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
  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s).

  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of FindShellTrayWindow 1 IoCs
  • Suspicious use of SendNotifyMessage 1 IoCs
  • Suspicious use of WriteProcessMemory 2 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\client.exe
    "C:\Users\Admin\AppData\Local\Temp\client.exe"
    1⤵
    • Drops file in System32 directory
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:656
    • C:\Windows\system32\Client.exe
      "C:\Windows\system32\Client.exe"
      2⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      • Suspicious use of FindShellTrayWindow
      • Suspicious use of SendNotifyMessage
      PID:2288

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads

  • C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\Client.exe.log

    Filesize

    1KB

    MD5

    b4e91d2e5f40d5e2586a86cf3bb4df24

    SHA1

    31920b3a41aa4400d4a0230a7622848789b38672

    SHA256

    5d8af3c7519874ed42a0d74ee559ae30d9cc6930aef213079347e2b47092c210

    SHA512

    968751b79a98961f145de48d425ea820fd1875bae79a725adf35fc8f4706c103ee0c7babd4838166d8a0dda9fbce3728c0265a04c4b37f335ec4eaa110a2b319

  • C:\Windows\System32\Client.exe

    Filesize

    3.1MB

    MD5

    4a603ec4e3c5a21400eaabac7c6401c6

    SHA1

    23b446721eacd0b6796407ca20bd1e01355ab41f

    SHA256

    566ba756b7fc2174fc195c05d9e0a36aa706e4ce397f890488227b7d0ad4ad7c

    SHA512

    070a5dd14bce16ba58eb65f3b3143fc7890f0e34f2ed7f3a1930e3fa8454ebcf615b43c819f16f4fc494676443bd409a3a57e8fe6e8f39ab02df5ace497eaea0

  • memory/656-0-0x00007FF84EE23000-0x00007FF84EE25000-memory.dmp

    Filesize

    8KB

  • memory/656-1-0x00000000007F0000-0x0000000000B14000-memory.dmp

    Filesize

    3.1MB

  • memory/656-2-0x00007FF84EE20000-0x00007FF84F8E2000-memory.dmp

    Filesize

    10.8MB

  • memory/656-9-0x00007FF84EE20000-0x00007FF84F8E2000-memory.dmp

    Filesize

    10.8MB

  • memory/2288-10-0x00007FF84EE20000-0x00007FF84F8E2000-memory.dmp

    Filesize

    10.8MB

  • memory/2288-11-0x00007FF84EE20000-0x00007FF84F8E2000-memory.dmp

    Filesize

    10.8MB

  • memory/2288-12-0x000000001C330000-0x000000001C380000-memory.dmp

    Filesize

    320KB

  • memory/2288-13-0x000000001C440000-0x000000001C4F2000-memory.dmp

    Filesize

    712KB

  • memory/2288-14-0x00007FF84EE20000-0x00007FF84F8E2000-memory.dmp

    Filesize

    10.8MB