General

  • Target

    PolyBuilds_1v1.exe

  • Size

    7KB

  • Sample

    241230-rg2fsazkbw

  • MD5

    69272798e19c17d2cde08c6b7b0c85c9

  • SHA1

    8812e949a8fc87f61cc1322f19f4d40f60cf5a2a

  • SHA256

    ae9431a46bf72d62b2f5a6662bdaa123d9a082235ee759ba5e4fc91eaba68f68

  • SHA512

    c8b76a813868bf6de69a4cf284152460d429e3a890179c1defd6855133a12abf50c677f4f8d3109aa0c21265893e144385260bdebef542003a02ee9106318588

  • SSDEEP

    96:HPMqv2qCKvN80OMS8v4eDR8mH7IRPOlkjDd/MNiBoYbiMxlpV3COZ1Rf+p6G:HxTOMS8v4dmbIhOwFfrh7V3TZDf+

Malware Config

Extracted

Family

xworm

Attributes
  • Install_directory

    %AppData%

  • install_file

    RtkAudUService64.exe

  • pastebin_url

    https://pastebin.com/raw/6ZBHT1SN

Targets

    • Target

      PolyBuilds_1v1.exe

    • Size

      7KB

    • MD5

      69272798e19c17d2cde08c6b7b0c85c9

    • SHA1

      8812e949a8fc87f61cc1322f19f4d40f60cf5a2a

    • SHA256

      ae9431a46bf72d62b2f5a6662bdaa123d9a082235ee759ba5e4fc91eaba68f68

    • SHA512

      c8b76a813868bf6de69a4cf284152460d429e3a890179c1defd6855133a12abf50c677f4f8d3109aa0c21265893e144385260bdebef542003a02ee9106318588

    • SSDEEP

      96:HPMqv2qCKvN80OMS8v4eDR8mH7IRPOlkjDd/MNiBoYbiMxlpV3COZ1Rf+p6G:HxTOMS8v4dmbIhOwFfrh7V3TZDf+

    • Detect Xworm Payload

    • Suspicious use of NtCreateUserProcessOtherParentProcess

    • Xworm

      Xworm is a remote access trojan written in C#.

    • Xworm family

    • Downloads MZ/PE file

    • Sets service image path in registry

    • Checks BIOS information in registry

      BIOS information is often read in order to detect sandboxing environments.

    • Checks computer location settings

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

    • Executes dropped EXE

    • Indicator Removal: Clear Windows Event Logs

      Clear Windows Event Logs to hide the activity of an intrusion.

    • Loads dropped DLL

    • Command and Scripting Interpreter: PowerShell

      Using powershell.exe command.

    • Enumerates connected drives

      Attempts to read the root path of hard drives other than the default C: drive.

    • Legitimate hosting services abused for malware hosting/C2

    • Looks up external IP address via web service

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

    • Writes to the Master Boot Record (MBR)

      Bootkits write to the MBR to gain persistence at a level below the operating system.

    • Drops file in System32 directory

    • Suspicious use of SetThreadContext

MITRE ATT&CK Enterprise v15

Tasks