Analysis

  • max time kernel
    899s
  • max time network
    889s
  • platform
    windows11-ltsc_2024_x64
  • resource
    win11ltsc2024-20260911-en
  • resource tags

    arch:x64arch:x86image:win11ltsc2024-20260911-enlocale:en-usos:windows11-ltsc_2024-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
  • Boot or Logon Autostart Execution: Active Setup 2 TTPs 1 IoCs

    Adversaries may achieve persistence by adding a Registry key to the Active Setup of the local machine.

  • Executes dropped EXE 16 IoCs
  • Adds Run key to start application 2 TTPs 1 IoCs
  • Enumerates connected drives 3 TTPs 2 IoCs

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

  • Enumerates physical storage devices 1 TTPs

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

  • Checks SCSI registry key(s) 3 TTPs 62 IoCs

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

  • Modifies Internet Explorer settings 1 TTPs 1 IoCs
  • Modifies registry class 38 IoCs
  • Scheduled Task/Job: Scheduled Task 1 TTPs 1 IoCs

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

  • Suspicious behavior: EnumeratesProcesses 2 IoCs
  • Suspicious use of AdjustPrivilegeToken 55 IoCs
  • Suspicious use of FindShellTrayWindow 54 IoCs
  • Suspicious use of SendNotifyMessage 40 IoCs
  • Suspicious use of SetWindowsHookEx 3 IoCs
  • Suspicious use of WriteProcessMemory 2 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.

  • Uses Volume Shadow Copy WMI provider

    The Volume Shadow Copy service is used to manage backups/snapshots.

  • Uses Volume Shadow Copy service COM API

    The Volume Shadow Copy service is used to manage backups/snapshots.

Processes

  • C:\Users\Admin\AppData\Local\Temp\MasonClient.exe
    "C:\Users\Admin\AppData\Local\Temp\MasonClient.exe"
    1⤵
    • Adds Run key to start application
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:792
    • 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:4764
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    C:\Users\Admin\AppData\Roaming\MasonClient.exe
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4388
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4348
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:1072
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:2148
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:5400
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:4660
  • C:\Users\Admin\AppData\Roaming\MasonClient.exe
    "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
    1⤵
    • Executes dropped EXE
    • Suspicious use of AdjustPrivilegeToken
    PID:5412
  • C:\Windows\system32\svchost.exe
    C:\Windows\system32\svchost.exe -k GPSvcGroup
    1⤵
      PID:1072
    • C:\Users\Admin\AppData\Roaming\MasonClient.exe
      "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
      1⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      PID:240
    • C:\Windows\system32\sihost.exe
      sihost.exe
      1⤵
      • Suspicious use of FindShellTrayWindow
      • Suspicious use of WriteProcessMemory
      PID:4620
      • C:\Windows\explorer.exe
        explorer.exe /LOADSAVEDWINDOWS
        2⤵
        • Boot or Logon Autostart Execution: Active Setup
        • Enumerates connected drives
        • Checks SCSI registry key(s)
        • Modifies Internet Explorer settings
        • Modifies registry class
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        • Suspicious use of FindShellTrayWindow
        • Suspicious use of SendNotifyMessage
        • Suspicious use of SetWindowsHookEx
        PID:3088
    • C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\SearchHost.exe
      "C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\SearchHost.exe" -ServerName:CortanaUI.AppXstmwaab17q5s3y22tp6apqz7a45vwv65.mca
      1⤵
      • Modifies registry class
      • Suspicious use of SetWindowsHookEx
      PID:932
    • C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost.exe
      "C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost.exe" -ServerName:App.AppXywbrabmsek0gm3tkwpr5kwzbs55tkqay.mca
      1⤵
      • Modifies registry class
      • Suspicious use of SetWindowsHookEx
      PID:6080
    • C:\Users\Admin\AppData\Roaming\MasonClient.exe
      "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
      1⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      PID:2912
    • C:\Users\Admin\AppData\Roaming\MasonClient.exe
      "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
      1⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      PID:1008
    • C:\Users\Admin\AppData\Roaming\MasonClient.exe
      "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
      1⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      PID:5704
    • C:\Users\Admin\AppData\Roaming\MasonClient.exe
      "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
      1⤵
      • Executes dropped EXE
      • Suspicious use of AdjustPrivilegeToken
      PID:6108
    • C:\Windows\System32\SecurityHealthHost.exe
      \\?\C:\Windows\System32\SecurityHealthHost.exe {08728914-3F57-4D52-9E31-49DAECA5A80A} -Embedding
      1⤵
        PID:2920
      • C:\Users\Admin\AppData\Roaming\MasonClient.exe
        "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of AdjustPrivilegeToken
        PID:3424
      • C:\Users\Admin\AppData\Roaming\MasonClient.exe
        "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of AdjustPrivilegeToken
        PID:1568
      • C:\Users\Admin\AppData\Roaming\MasonClient.exe
        "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of AdjustPrivilegeToken
        PID:4660
      • C:\Users\Admin\AppData\Roaming\MasonClient.exe
        "C:\Users\Admin\AppData\Roaming\MasonClient.exe"
        1⤵
        • Executes dropped EXE
        • Suspicious use of AdjustPrivilegeToken
        PID:1804

      Network

            MITRE ATT&CK Enterprise v16

            Replay Monitor

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            Downloads

            prep_Activatable Class_Hermes_perf.cache

            • Path C:\Users\Admin\AppData\Local\Packages\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\TempState\prep_Activatable Class_Hermes_perf.cache
            • Size 599B
            • SHA256 b536a3dae9ea5c69081f0491eed829e3b57e32401fdf49a63031bcd6b20e6fdb
            • MD5 SHA1 SHA512 TLSH

            MasonClient.exe

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

            memory/792-8-0x00007FFB5C420000-0x00007FFB5CDC4000-memory.dmp

            memory/792-1-0x0000000000DE0000-0x0000000000DF2000-memory.dmp

            memory/792-4-0x00007FFB5C420000-0x00007FFB5CDC4000-memory.dmp

            memory/792-5-0x00007FFB5C420000-0x00007FFB5CDC4000-memory.dmp

            memory/792-2-0x00007FFB5C420000-0x00007FFB5CDC4000-memory.dmp

            memory/792-3-0x00007FFB5C420000-0x00007FFB5CDC4000-memory.dmp

            memory/792-0-0x00007FFB5C5AF000-0x00007FFB5C5B0000-memory.dmp

            memory/932-85-0x000001FC942F0000-0x000001FC94310000-memory.dmp

            memory/932-20-0x000001FC801E0000-0x000001FC802E0000-memory.dmp

            memory/932-54-0x000001FC94000000-0x000001FC94100000-memory.dmp

            memory/932-71-0x000001FC81E00000-0x000001FC81E20000-memory.dmp

            memory/932-52-0x000001FC81CD0000-0x000001FC81CF0000-memory.dmp

            memory/4388-9-0x00007FFB5C420000-0x00007FFB5CDC4000-memory.dmp

            memory/4388-7-0x00007FFB5C420000-0x00007FFB5CDC4000-memory.dmp

            memory/6080-216-0x000001D30BB80000-0x000001D30BE3C000-memory.dmp

            memory/6080-225-0x000001D30BB80000-0x000001D30BE3C000-memory.dmp