Analysis

  • max time kernel
    142s
  • max time network
    147s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20231127-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20231127-enlocale:en-usos:windows10-2004-x64system
  • submitted
    28-11-2023 13:09

General

  • Target

    Client-built.exe

  • Size

    349KB

  • MD5

    2207ba09525cf5c4b7b7e09359bd6118

  • SHA1

    2c266c94899b4cb038e812ed1c067b47979399bd

  • SHA256

    fe00b66746e04dc422da7033d22c5c4f516a41713de90c61580d4e4ec30469ed

  • SHA512

    628a46802656589b4b90285b927756f9855718487bc317b194304d751cf9b8262fa1f9c805ae5b194b4f279f17ef02b4cab370a6e728aef8f6bb992d3a6eadeb

  • SSDEEP

    6144:FKMJx4pweP7kJS3iCxPMQ0PTCo6t6RXzxNTpGbGttZoap9O:FKoS5xM3PTCoa6Jz9btkm9O

Malware Config

Extracted

Family

quasar

Version

1.3.0.0

Botnet

Office04

C2

223.27.104.5:4782

Mutex

QSR_MUTEX_TKIGmUQNaov60j8Osd

Attributes
  • encryption_key

    fNvCkOKAiWAMHbrA0e7Y

  • install_name

    Client.exe

  • log_directory

    Logs

  • reconnect_delay

    3000

  • startup_key

    Quasar Client Startup

  • subdirectory

    SubDir

Signatures

  • Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 3 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:4396
    • C:\Windows\SysWOW64\schtasks.exe
      "schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Users\Admin\AppData\Local\Temp\Client-built.exe" /rl HIGHEST /f
      2⤵
      • Creates scheduled task(s)
      PID:4280
    • 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:1788
      • C:\Windows\SysWOW64\schtasks.exe
        "schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f
        3⤵
        • Creates scheduled task(s)
        PID:1292

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

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Downloads

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

    Filesize

    349KB

    MD5

    2207ba09525cf5c4b7b7e09359bd6118

    SHA1

    2c266c94899b4cb038e812ed1c067b47979399bd

    SHA256

    fe00b66746e04dc422da7033d22c5c4f516a41713de90c61580d4e4ec30469ed

    SHA512

    628a46802656589b4b90285b927756f9855718487bc317b194304d751cf9b8262fa1f9c805ae5b194b4f279f17ef02b4cab370a6e728aef8f6bb992d3a6eadeb

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

    Filesize

    349KB

    MD5

    2207ba09525cf5c4b7b7e09359bd6118

    SHA1

    2c266c94899b4cb038e812ed1c067b47979399bd

    SHA256

    fe00b66746e04dc422da7033d22c5c4f516a41713de90c61580d4e4ec30469ed

    SHA512

    628a46802656589b4b90285b927756f9855718487bc317b194304d751cf9b8262fa1f9c805ae5b194b4f279f17ef02b4cab370a6e728aef8f6bb992d3a6eadeb

  • memory/1788-15-0x0000000004F50000-0x0000000004F60000-memory.dmp

    Filesize

    64KB

  • memory/1788-13-0x00000000745C0000-0x0000000074D70000-memory.dmp

    Filesize

    7.7MB

  • memory/1788-19-0x0000000004F50000-0x0000000004F60000-memory.dmp

    Filesize

    64KB

  • memory/1788-18-0x00000000745C0000-0x0000000074D70000-memory.dmp

    Filesize

    7.7MB

  • memory/1788-17-0x0000000006680000-0x000000000668A000-memory.dmp

    Filesize

    40KB

  • memory/4396-1-0x00000000745C0000-0x0000000074D70000-memory.dmp

    Filesize

    7.7MB

  • memory/4396-2-0x0000000005660000-0x0000000005C04000-memory.dmp

    Filesize

    5.6MB

  • memory/4396-3-0x00000000050B0000-0x0000000005142000-memory.dmp

    Filesize

    584KB

  • memory/4396-14-0x00000000745C0000-0x0000000074D70000-memory.dmp

    Filesize

    7.7MB

  • memory/4396-7-0x00000000065F0000-0x000000000662C000-memory.dmp

    Filesize

    240KB

  • memory/4396-0-0x00000000005F0000-0x000000000064E000-memory.dmp

    Filesize

    376KB

  • memory/4396-6-0x00000000061B0000-0x00000000061C2000-memory.dmp

    Filesize

    72KB

  • memory/4396-5-0x0000000005480000-0x00000000054E6000-memory.dmp

    Filesize

    408KB

  • memory/4396-4-0x0000000005270000-0x0000000005280000-memory.dmp

    Filesize

    64KB