General

  • Target

    Client-built.exe

  • Size

    3.1MB

  • Sample

    241124-xzmy1a1kdm

  • MD5

    d736427dd2ccd3f8a536d5cf69827f6f

  • SHA1

    20db2442845c8559801de82434b3af89b6545c4a

  • SHA256

    0463f6a7f96dd95ae2352e658a17210f6242fec676cacd4c9a8042e1b040560e

  • SHA512

    822bdf46a2f950f42a8c17afe9cf1ca27685fb44e180966871df2f2da08b872a10e72e5c892b901d3c1a9f2421ed91ac14b452d0d87fff8146e3839740fb0112

  • SSDEEP

    49152:fvvlL26AaNeWgPhlmVqvMQ7XSKPmEqf5P+rk/GLoGABTHHB72eh2NT:fv9L26AaNeWgPhlmVqkQ7XSKZqU

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

Name1442-37611.portmap.host:37611

Mutex

f21583dc-cd85-4a94-b7ea-858f2e9d6287

Attributes
  • encryption_key

    A43011D93D39774DA187A9FA7731DE56F484D345

  • install_name

    Client.exe

  • log_directory

    Logs

  • reconnect_delay

    3000

  • startup_key

    Quasar Client Startup

  • subdirectory

    SubDir

Extracted

Family

xworm

C2

127.0.0.1:37611

Name1442-37611.portmap.host:37611

Attributes
  • Install_directory

    %AppData%

  • install_file

    svchost.exe

Targets

    • Target

      Client-built.exe

    • Size

      3.1MB

    • MD5

      d736427dd2ccd3f8a536d5cf69827f6f

    • SHA1

      20db2442845c8559801de82434b3af89b6545c4a

    • SHA256

      0463f6a7f96dd95ae2352e658a17210f6242fec676cacd4c9a8042e1b040560e

    • SHA512

      822bdf46a2f950f42a8c17afe9cf1ca27685fb44e180966871df2f2da08b872a10e72e5c892b901d3c1a9f2421ed91ac14b452d0d87fff8146e3839740fb0112

    • SSDEEP

      49152:fvvlL26AaNeWgPhlmVqvMQ7XSKPmEqf5P+rk/GLoGABTHHB72eh2NT:fv9L26AaNeWgPhlmVqkQ7XSKZqU

    • Contains code to disable Windows Defender

      A .NET executable tasked with disabling Windows Defender capabilities such as realtime monitoring, blocking at first seen, etc.

    • Detect Xworm Payload

    • Quasar RAT

      Quasar is an open source Remote Access Tool.

    • Quasar family

    • Quasar payload

    • Xworm

      Xworm is a remote access trojan written in C#.

    • Xworm family

    • Command and Scripting Interpreter: PowerShell

      Run Powershell to modify Windows Defender settings to add exclusions for file extensions, paths, and processes.

    • Checks computer location settings

      Looks up country code configured in the registry, likely geofence.

    • Executes dropped EXE

    • Reads WinSCP keys stored on the system

      Tries to access WinSCP stored sessions.

    • Reads user/profile data of web browsers

      Infostealers often target stored browser data, which can include saved credentials etc.

    • Adds Run key to start application

    • Looks up external IP address via web service

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

    • Drops file in System32 directory

MITRE ATT&CK Enterprise v15

Tasks