Analysis
- user interaction
yes - max time kernel
149s - max time network
149s - platform
windows10-2004_x64 - resource
win10v2004-20260911-en - resource tags
- submitted
02/10/2026, 17:44
General
- Target MasonClient.exe
- Size 89KB
- Sample261002-wbc88avyax
- SHA256 f800bd1157b254086f02d1dab40a219e8209581f2e5f3dc3085aaf4655afb531
Malware Config
Extracted
-
neptunerat
-
92.96.191.46:6767
-
filename
USB.exe
-
group
MasonGroup
-
key
vVOmRZbg1YJMe5L0
-
rat_name
MasonRAT
Signatures
- Family: DonutLoader
DonutLoader is a position-independent code that enables in-memory execution of VBScript, JScript, EXE, DLL files and dotNET assemblies.
- Family: NeptuneRAT, MasonRAT
NeptuneRAT aka MasonRAT is a trojan written in C#.
- Detects DonutLoader 1 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 3 IoCs
- Adds Run key to start application 2 TTPs 1 IoCs
- Enumerates video capture drivers 2 TTPs 1 IoCs
Queries the legacy Video for Windows capture drivers. This is commonly abused by RATs to check for available webcams on the system before reporting to their C2.
- Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).
- Reads the TCP/IP host and domain name from the registry 1 TTPs 2 IoCs
The configured hostname and DNS domain identify the machine and are commonly collected to profile a host before it reports in.
- System Location Discovery: System Language Discovery 1 TTPs 1 IoCs
Attempt gather information about the system language of a victim in order to infer the geographical location of that host.
- 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 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.
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
- Enumerates video capture drivers
- Reads the TCP/IP host and domain name from the registry
- 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\Local\Temp\tmpD0C3.tmp.exe"C:\Users\Admin\AppData\Local\Temp\tmpD0C3.tmp.exe"2⤵
- Executes dropped EXE
- System Location Discovery: System Language Discovery
-
-
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
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
-
C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
Network
MITRE ATT&CK Enterprise v16
Persistence
Boot or Logon Autostart Execution
1Registry Run Keys / Startup Folder
1Scheduled Task/Job
1Scheduled Task
1Privilege Escalation
Boot or Logon Autostart Execution
1Registry Run Keys / Startup Folder
1Scheduled Task/Job
1Scheduled Task
1Replay Monitor
Loading Replay Monitor...
Downloads
MasonClient.exe.log
tmpD0C3.tmp.exe
MasonClient.exe
memory/3224-36-0x0000000000650000-0x000000000065A000-memory.dmp
memory/3304-6-0x000000001BCD0000-0x000000001BCE0000-memory.dmp
memory/3304-5-0x000000001BCD0000-0x000000001BCE0000-memory.dmp
memory/3304-0-0x0000000000E90000-0x0000000000EAC000-memory.dmp
memory/3304-16-0x000000001BCD0000-0x000000001BCE0000-memory.dmp
memory/3304-18-0x000000001BCD0000-0x000000001BCE0000-memory.dmp
memory/3304-17-0x000000001BCD0000-0x000000001BCE0000-memory.dmp
memory/3304-4-0x0000000003040000-0x0000000003054000-memory.dmp
memory/3304-24-0x0000000001660000-0x0000000001668000-memory.dmp
memory/3304-3-0x000000001BCD0000-0x000000001BCE0000-memory.dmp
memory/3304-1-0x0000000003000000-0x0000000003016000-memory.dmp
memory/4488-12-0x000000001AD80000-0x000000001AD90000-memory.dmp
memory/4488-13-0x000000001AD80000-0x000000001AD90000-memory.dmp