Analysis
- user interaction
yes - max time kernel
48s - max time network
63s - platform
windows10-ltsc_2021_x64 - resource
win10ltsc2021-20260911-en - resource tags
- submitted
24/10/2026, 19:08
Errors
General
- Target MasonClient.exe
- Size 48KB
- Sample261024-xtjz6afe95
- SHA256 67d5dbfb6f6970c37d497a53e670ea13c4275f8b957845f99e25147ab3a2db07
Malware Config
Extracted
-
neptunerat
-
jhhmcdxi4o.localto.net:5028
-
filename
USB.exe
-
group
MasonGroup
-
key
l8TE3cLoYsTZpNnB
-
rat_name
MasonRAT
Signatures
- Family: NeptuneRAT, MasonRAT
NeptuneRAT aka MasonRAT is a trojan written in C#.
- Detects NeptuneRAT stealer 2 IoCs
- Disables Task Manager via registry modification
- Checks computer location settings 2 TTPs 4 IoCs
Looks up country code configured in the registry, likely geofence.
- Executes dropped EXE 9 IoCs
- Adds Run key to start application 2 TTPs 1 IoCs
- Writes to the Master Boot Record (MBR) 1 TTPs 1 IoCs
Bootkits write to the MBR to gain persistence at a level below the operating system.
- Drops file in System32 directory 2 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 4 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 4 IoCs
- Suspicious use of WriteProcessMemory 8 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
-
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C:\Users\Admin\AppData\Local\Temp\tmp100.tmp.COM"C:\Users\Admin\AppData\Local\Temp\tmp100.tmp.COM"2⤵
- Checks computer location settings
- Executes dropped EXE
- Suspicious use of WriteProcessMemory
-
C:\Users\Admin\AppData\Local\Temp\MBR2.exe"C:\Users\Admin\AppData\Local\Temp\MBR2.exe"3⤵
- Checks computer location settings
- Executes dropped EXE
- Drops file in System32 directory
- Suspicious use of WriteProcessMemory
-
C:\Windows\System32\MatrixMBR.exe"C:\Windows\System32\MatrixMBR.exe"4⤵
- Checks computer location settings
- Executes dropped EXE
- Suspicious use of WriteProcessMemory
-
C:\Users\Admin\AppData\Local\Temp\GDI.exe"C:\Users\Admin\AppData\Local\Temp\GDI.exe"5⤵
- Executes dropped EXE
- System Location Discovery: System Language Discovery
-
-
C:\Users\Admin\AppData\Local\Temp\MBR.exe"C:\Users\Admin\AppData\Local\Temp\MBR.exe"5⤵
- Executes dropped EXE
- Writes to the Master Boot Record (MBR)
- System Location Discovery: System Language Discovery
- Suspicious use of AdjustPrivilegeToken
-
-
-
-
C:\Users\Admin\AppData\Local\Temp\TROLL5.exe"C:\Users\Admin\AppData\Local\Temp\TROLL5.exe"3⤵
- Executes dropped EXE
- System Location Discovery: System Language Discovery
-
-
C:\Users\Admin\AppData\Local\Temp\TROLL2.exe"C:\Users\Admin\AppData\Local\Temp\TROLL2.exe"3⤵
- 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.exe"C:\Users\Admin\AppData\Roaming\MasonClient.exe"1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
-
C:\Windows\system32\AUDIODG.EXEC:\Windows\system32\AUDIODG.EXE 0x4c8 0x4b01⤵
Network
MITRE ATT&CK Enterprise v16
Persistence
Boot or Logon Autostart Execution
1Registry Run Keys / Startup Folder
1Pre-OS Boot
1Bootkit
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
GDI.exe
MBR.exe
MBR2.exe
TROLL2.exe
TROLL5.exe
tmp100.tmp.COM
MasonClient.exe
MatrixMBR.exe
memory/1096-78-0x0000000000400000-0x000000000041D000-memory.dmp
memory/1500-15-0x0000000000740000-0x000000000082C000-memory.dmp
memory/1500-16-0x000000001B2A0000-0x000000001B384000-memory.dmp
memory/3048-55-0x0000000000D30000-0x0000000000D6A000-memory.dmp
memory/4524-0-0x0000000000370000-0x0000000000382000-memory.dmp
memory/4524-4-0x000000001B070000-0x000000001B080000-memory.dmp
memory/4524-30-0x000000001B600000-0x000000001B68E000-memory.dmp
memory/4524-1-0x000000001B070000-0x000000001B080000-memory.dmp
memory/6032-64-0x0000000004C10000-0x0000000004CA2000-memory.dmp
memory/6032-65-0x0000000004BA0000-0x0000000004BAA000-memory.dmp
memory/6032-63-0x00000000051C0000-0x0000000005766000-memory.dmp
memory/6032-62-0x0000000000100000-0x00000000001B8000-memory.dmp
memory/6048-83-0x0000000000A00000-0x0000000000A46000-memory.dmp
memory/6080-106-0x0000000000B10000-0x0000000000B18000-memory.dmp