Analysis

  • user interaction
    yes
  • max time kernel
    898s
  • max time network
    889s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20260911-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20260911-enlocale:en-usos:windows10-2004-x64systemwindows
  • submitted
    16/09/2026, 22:39

General

  • Target
    MasonClient.exe
  • Size 49KB
  • Sample260916-2k66jsfb63
  • SHA256 3fd1677145bc6e50d8b9d26d5369360e84c9063edcf8aae7972ee029fd0d5e83
  • MD5 SHA1 SHA512 SSDEEP TLSH

Malware Config

Extracted

Family
  • neptunerat

C2
  • 188.209.211.120:8080

Attributes
  • filename

    USB.exe

  • group

    MasonGroup

  • key

    dzLRNpkgEBxWJ2Jm

  • rat_name

    MasonRAT

Signatures

  • Family: NeptuneRAT, MasonRAT

    NeptuneRAT aka MasonRAT is a trojan written in C#.

  • Detects NeptuneRAT stealer 2 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

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

  • Executes dropped EXE 16 IoCs
  • Adds Run key to start application 2 TTPs 1 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Scheduled Task/Job: Scheduled Task 1 TTPs 1 IoCs

    Schtasks is often used by malware for persistence or to perform post-infection execution.

  • Suspicious use of AdjustPrivilegeToken 17 IoCs
  • Suspicious use of WriteProcessMemory 1 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\MasonClient.exe
    "C:\Users\Admin\AppData\Local\Temp\MasonClient.exe"
    1⤵
    • Checks computer location settings
    • Adds Run key to start application
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:4540
    • C:\Windows\System32\schtasks.exe
      "C:\Windows\System32\schtasks.exe" /create /f /sc minute /mo 1 /tn "MasonClient" /tr "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
      2⤵
      • Scheduled Task/Job: Scheduled Task
      PID:1808
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:3580
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:3916
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:1396
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4064
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:5052
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:444
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:2404
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4164
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4860
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:2656
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4712
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4888
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:1292
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:2812
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4332
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:1668

Network

        MITRE ATT&CK Enterprise v16

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        MasonClient.exe.log

        • Path C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\MasonClient.exe.log
        • Size 654B
        • SHA256 e1b91642d85d98124a6a31f710e137ab7fd90dec30e74a05ab7fcf3b7887dced
        • MD5 SHA1 SHA512 TLSH

        MasonClient.exe

        • Path C:\Users\Admin\AppData\Roaming\MasonClient.exe
        • Size 49KB
        • SHA256 3fd1677145bc6e50d8b9d26d5369360e84c9063edcf8aae7972ee029fd0d5e83
        • MD5 SHA1 SHA512 SSDEEP TLSH

        memory/4540-0-0x0000000000E30000-0x0000000000E42000-memory.dmp

        memory/4540-2-0x000000001BA40000-0x000000001BA50000-memory.dmp

        memory/4540-6-0x000000001BA40000-0x000000001BA50000-memory.dmp