Resubmissions

04/11/2026, 06:49

261104-hlvz5aax8q10

04/11/2026, 06:47

261104-hkn57acf983

04/11/2026, 06:44

261104-hhmvcacf9210

General

  • Target
    https://gofile.io/d/i2Gc7uW5
  • Sample261104-hhmvcacf92

Malware Config

Extracted

Family
  • neptunerat

C2
  • 2.57.19.42:818

Attributes
  • filename

    MasonUSB.exe

  • group

    MasonGroup

  • key

    DsKcRUxvrzkF9yJ8

  • rat_name

    MasonRAT

Extracted

Family
  • umbral

Version
  • v1.3

C2
  • https://canary.discord.com/api/webhooks/1562473509593153577/r7i5tm1sbgZRZEuumb2MFbh7ZKceAC_yRpQBDMlMQqlXzqSBaR9meo_ynD23pH3kk4L5

Targets

    • Detects NeptuneRAT stealer

    • Detects Umbral payload

    • Family: NeptuneRAT, MasonRAT

      NeptuneRAT aka MasonRAT is a trojan written in C#.

    • Family: Umbral

      Umbral stealer is an open-source modular stealer written in C#.

    • Downloads MZ/PE file

    • Sets service image path in registry

      This determines the executable launched when a service starts. It can be used to establish persistence.

    • 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.

    • Adds Run key to start application

    • Contacts third-party web service commonly abused for C2

      Legitimate web (hosting) services can be abused by malware authors to host malware or C2s.

    • 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

MITRE ATT&CK Enterprise v16

Tasks