Analysis
- max time kernel
53s - max time network
54s - platform
windows10-2004_x64 - resource
win10v2004-20260911-en - resource tags
- submitted
16/09/2026, 10:04
General
- Target MasonClient.exe
- Size 48KB
- Sample260916-l3x3laydmc
- SHA256 0868ade302ddc24703049e4274d51c6f0295e4007ed4de11c910ee5a40f44ec0
Malware Config
Extracted
-
neptunerat
-
89.190.158.37:911
-
filename
USB.exe
-
group
<Neptune>
-
key
3C62Outx4Gy0Zewc
-
rat_name
<123456789>
Signatures
- Family: NeptuneRAT, MasonRAT
NeptuneRAT aka MasonRAT is a trojan written in C#.
- Family: Xworm
Xworm is a remote access trojan written in C#.
- Detect Xworm Payload 2 IoCs
- 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 2 IoCs
- Adds Run key to start application 2 TTPs 1 IoCs
- Contacts third-party web service commonly abused for C2 1 TTPs 1 IoCs
Legitimate web (hosting) services can be abused by malware authors to host malware or C2s.
- 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 3 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
-
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
-
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
Network
MITRE ATT&CK Enterprise v16
Persistence
Boot or Logon Autostart Execution
1Registry Run Keys / Startup Folder
1Scheduled Task/Job
1Scheduled Task
1Replay Monitor
Loading Replay Monitor...
Downloads
MasonClient.exe.log
MasonClient.exe
memory/1232-0-0x0000000000070000-0x0000000000082000-memory.dmp
memory/1232-2-0x000000001AEA0000-0x000000001AEB0000-memory.dmp
memory/1232-6-0x000000001AEA0000-0x000000001AEB0000-memory.dmp