Analysis

  • max time kernel
    1800s
  • max time network
    1507s
  • platform
    windows11-21h2_x64
  • resource
    win11-20240508-en
  • resource tags

    arch:x64arch:x86image:win11-20240508-enlocale:en-usos:windows11-21h2-x64system
  • submitted
    20-05-2024 20:02

General

  • Target

    LastExternal.exe

  • Size

    3.1MB

  • MD5

    d89bcb84ff94321d131f8f826a7177f5

  • SHA1

    3612cb183adeb6225f7ae0ac4425e8072baebb9c

  • SHA256

    7c7d0a81bb0037aa2d509217e0464572444cb79154470e72f364755fab99b7d4

  • SHA512

    2830d50245e266338a90163e9945a91623bc839d0d4657cdd6d6d8b8970c981e0eeaa1778f2ed5ecf61bcd870c03aa0a9d2e6dce0be461d13e6dfad17db7cf0d

  • SSDEEP

    49152:yv6Y52fyaSZOrPWluWBuGG5g5h0kxG1v1LoGKd+THHB72eh2NT:yvP52fyaSZOrPWluWBDG5g5h0kxK

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Cw2

C2

127.0.0.1:8080

Mutex

eeb96fcd-c654-4ba2-9a84-d3d5cfa5eee3

Attributes
  • encryption_key

    7A857EF3A3EB39AF399F1F3800FB9F842DC83C9E

  • install_name

    Client.exe

  • log_directory

    Logs

  • reconnect_delay

    1

  • startup_key

    W

  • subdirectory

    SubDir

Signatures

  • Quasar RAT

    Quasar is an open source Remote Access Tool.

  • Quasar payload 2 IoCs
  • Executes dropped EXE 1 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • 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 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\LastExternal.exe
    "C:\Users\Admin\AppData\Local\Temp\LastExternal.exe"
    1⤵
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:3984
    • C:\Windows\SYSTEM32\schtasks.exe
      "schtasks" /create /tn "W" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f
      2⤵
      • Creates scheduled task(s)
      PID:536
    • 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 FindShellTrayWindow
      • Suspicious use of SendNotifyMessage
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      PID:3860
      • C:\Windows\SYSTEM32\schtasks.exe
        "schtasks" /create /tn "W" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f
        3⤵
        • Creates scheduled task(s)
        PID:4920

Network

MITRE ATT&CK Matrix ATT&CK v13

Execution

Scheduled Task/Job

1
T1053

Persistence

Scheduled Task/Job

1
T1053

Privilege Escalation

Scheduled Task/Job

1
T1053

Discovery

System Information Discovery

1
T1082

Query Registry

1
T1012

Replay Monitor

Loading Replay Monitor...

Downloads

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

    3.1MB

    MD5

    d89bcb84ff94321d131f8f826a7177f5

    SHA1

    3612cb183adeb6225f7ae0ac4425e8072baebb9c

    SHA256

    7c7d0a81bb0037aa2d509217e0464572444cb79154470e72f364755fab99b7d4

    SHA512

    2830d50245e266338a90163e9945a91623bc839d0d4657cdd6d6d8b8970c981e0eeaa1778f2ed5ecf61bcd870c03aa0a9d2e6dce0be461d13e6dfad17db7cf0d

  • memory/3860-10-0x00007FFF13FF0000-0x00007FFF14AB2000-memory.dmp
    Filesize

    10.8MB

  • memory/3860-11-0x00007FFF13FF0000-0x00007FFF14AB2000-memory.dmp
    Filesize

    10.8MB

  • memory/3860-12-0x000000001C2D0000-0x000000001C320000-memory.dmp
    Filesize

    320KB

  • memory/3860-13-0x000000001C3E0000-0x000000001C492000-memory.dmp
    Filesize

    712KB

  • memory/3860-14-0x00007FFF13FF0000-0x00007FFF14AB2000-memory.dmp
    Filesize

    10.8MB

  • memory/3860-15-0x00007FFF13FF0000-0x00007FFF14AB2000-memory.dmp
    Filesize

    10.8MB

  • memory/3984-0-0x00007FFF13FF3000-0x00007FFF13FF5000-memory.dmp
    Filesize

    8KB

  • memory/3984-1-0x0000000000D00000-0x0000000001024000-memory.dmp
    Filesize

    3.1MB

  • memory/3984-2-0x00007FFF13FF0000-0x00007FFF14AB2000-memory.dmp
    Filesize

    10.8MB

  • memory/3984-9-0x00007FFF13FF0000-0x00007FFF14AB2000-memory.dmp
    Filesize

    10.8MB