Analysis
- user interaction
yes - max time kernel
125s - max time network
126s - platform
windows10-2004_x64 - resource
win10v2004-20260911-en - resource tags
- submitted
24/10/2026, 08:43
Errors
General
- Target MasonClient.exe
- Size 48KB
- Sample261024-kmt6bsef29
- SHA256 5d8fae478eff7164a85415b030a758cf623d9a64c7725ea10419933780e2273b
Malware Config
Extracted
-
neptunerat
-
jhhmcdxi4o.localto.net:2547
-
filename
USB.exe
-
group
MasonGroup
-
key
E6eknZOGNhzlMLIX
-
rat_name
MasonRAT
Signatures
- Family: NeptuneRAT, MasonRAT
NeptuneRAT aka MasonRAT is a trojan written in C#.
- 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 4 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.
- 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 5 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\tmpA663.tmp.exe"C:\Users\Admin\AppData\Local\Temp\tmpA663.tmp.exe"2⤵
- Executes dropped EXE
- Writes to the Master Boot Record (MBR)
- System Location Discovery: System Language Discovery
- 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⤵
- 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
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
tmpA663.tmp.exe
MasonClient.exe
memory/4524-0-0x00000000002C0000-0x00000000002D2000-memory.dmp
memory/4524-2-0x000000001B1F0000-0x000000001B200000-memory.dmp
memory/4524-6-0x000000001B1F0000-0x000000001B200000-memory.dmp
memory/4524-18-0x0000000000AA0000-0x0000000000AAA000-memory.dmp