Analysis
- max time kernel
898s - max time network
901s - platform
windows11-21h2_x64 - resource
win11-20260911-en - resource tags
arch:x64arch:x86image:win11-20260911-enlocale:en-usos:windows11-21h2-x64systemwindows - submitted
16/09/2026, 22:40
Behavioral task
behavioral1
Sample
MasonClient.exe
Resource
win10v2004-20260911-en
Behavioral task
behavioral2
Sample
MasonClient.exe
Resource
win10ltsc2021-20260911-en
Behavioral task
behavioral3
Sample
MasonClient.exe
Resource
win11-20260911-en
Behavioral task
behavioral4
Sample
MasonClient.exe
Resource
win11ltsc2024-20260911-en
General
- Target MasonClient.exe
- Size 49KB
- Sample260916-2l2mfsweph
- SHA256 3fd1677145bc6e50d8b9d26d5369360e84c9063edcf8aae7972ee029fd0d5e83
- MD5 d124ff038191eb90d3c747b945d3307f
- SHA1 8284b61252268780fb732a4b16d84193dc6e005d
- SHA512 08c32c463820de1d3bcaf456dac9354826aae098ebab4cf98581006ff13f39f980728aad41a9b268f5eecf73211ab9f05072e29ecf77d906a9221d68201e187b
- SSDEEP 1536:C3HEr1GtUtfuUnUk7XUNo57qp1XOcCXOchXOc8XOcVXOc1DVwZUOmUk+KmSKmwXP:C3HEr1GtUtfuUnUk7XUaZqp1XOcCXOc1
- TLSH T12733E78DE7D50121D6BF9EB119B31209C3B07AD34916C66F7CD841CB2B2BB984681BE7
- MD5 SHA1 SHA512 SSDEEP TLSH
Malware Config
Extracted
-
neptunerat
-
188.209.211.120:8080
-
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
resource yara_rule behavioral3/memory/4844-0-0x0000000000970000-0x0000000000982000-memory.dmp family_neptunerat behavioral3/files/0x00190000000256c3-4.dat family_neptunerat - Executes dropped EXE 16 IoCs
pid Process 5144 MasonClient.exe 3948 MasonClient.exe 960 MasonClient.exe 1456 MasonClient.exe 412 MasonClient.exe 4952 MasonClient.exe 988 MasonClient.exe 5080 MasonClient.exe 3768 MasonClient.exe 5804 MasonClient.exe 6016 MasonClient.exe 5056 MasonClient.exe 4008 MasonClient.exe 4576 MasonClient.exe 1812 MasonClient.exe 3320 MasonClient.exe - Adds Run key to start application 2 TTPs 1 IoCs
description ioc Process Set value (str) \REGISTRY\USER\S-1-5-21-2293636880-3790684622-1477845016-1000\Software\Microsoft\Windows\CurrentVersion\Run\MasonClient = "C:\\Users\\Admin\\AppData\\Roaming\\MasonClient.exe" MasonClient.exe - 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.
pid Process 5072 schtasks.exe - Suspicious use of AdjustPrivilegeToken 17 IoCs
description pid Process Token: SeDebugPrivilege 4844 MasonClient.exe Token: SeDebugPrivilege 5144 MasonClient.exe Token: SeDebugPrivilege 3948 MasonClient.exe Token: SeDebugPrivilege 960 MasonClient.exe Token: SeDebugPrivilege 1456 MasonClient.exe Token: SeDebugPrivilege 412 MasonClient.exe Token: SeDebugPrivilege 4952 MasonClient.exe Token: SeDebugPrivilege 988 MasonClient.exe Token: SeDebugPrivilege 5080 MasonClient.exe Token: SeDebugPrivilege 3768 MasonClient.exe Token: SeDebugPrivilege 5804 MasonClient.exe Token: SeDebugPrivilege 6016 MasonClient.exe Token: SeDebugPrivilege 5056 MasonClient.exe Token: SeDebugPrivilege 4008 MasonClient.exe Token: SeDebugPrivilege 4576 MasonClient.exe Token: SeDebugPrivilege 1812 MasonClient.exe Token: SeDebugPrivilege 3320 MasonClient.exe - Suspicious use of WriteProcessMemory 1 IoCs
description pid Process procid_target PID 4844 wrote to memory of 5072 4844 MasonClient.exe 80 - 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⤵
- Adds Run key to start application
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:4844 -
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:5072
-
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:5144
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:3948
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:960
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:1456
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:412
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:4952
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:988
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:5080
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:3768
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:5804
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:6016
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:5056
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:4008
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:4576
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:1812
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:3320
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
- Path C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\MasonClient.exe.log
- Size 654B
- SHA256 e31b18f21621d9983bfdf1ea3e53884a9d58b8ffd79e0e5790da6f3a81a8b9d3
- MD5 2cbbb74b7da1f720b48ed31085cbd5b8
- SHA1 79caa9a3ea8abe1b9c4326c3633da64a5f724964
- SHA512 ecf02d5240e0c1c005d3ab393aa7eff62bd498c2db5905157e2bf6d29e1b663228a9583950842629d1a4caef404c8941a0c7799b1a3bd1eb890a09fdb7efcff9
- TLSH T119F0A2302371E1C8C9263F422C0D2A4966AF474A7B50FE0C7694635DD825167AF313F3
- MD5 SHA1 SHA512 TLSH
- Path C:\Users\Admin\AppData\Roaming\MasonClient.exe
- Size 49KB
- SHA256 3fd1677145bc6e50d8b9d26d5369360e84c9063edcf8aae7972ee029fd0d5e83
- MD5 d124ff038191eb90d3c747b945d3307f
- SHA1 8284b61252268780fb732a4b16d84193dc6e005d
- SHA512 08c32c463820de1d3bcaf456dac9354826aae098ebab4cf98581006ff13f39f980728aad41a9b268f5eecf73211ab9f05072e29ecf77d906a9221d68201e187b
- SSDEEP 1536:C3HEr1GtUtfuUnUk7XUNo57qp1XOcCXOchXOc8XOcVXOc1DVwZUOmUk+KmSKmwXP:C3HEr1GtUtfuUnUk7XUaZqp1XOcCXOc1
- TLSH T12733E78DE7D50121D6BF9EB119B31209C3B07AD34916C66F7CD841CB2B2BB984681BE7
- MD5 SHA1 SHA512 SSDEEP TLSH