Analysis
- max time kernel
157s - max time network
166s - platform
windows10-2004_x64 - resource
win10v2004-20260911-en - resource tags
- submitted
24/10/2026, 08:51
Errors
General
- Target MasonClient.exe
- Size 48KB
- Sample261024-kr464aax6m
- SHA256 5d8fae478eff7164a85415b030a758cf623d9a64c7725ea10419933780e2273b
Malware Config
Extracted
-
neptunerat
-
jhhmcdxi4o.localto.net:2547
-
filename
USB.exe
-
group
MasonGroup
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key
E6eknZOGNhzlMLIX
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rat_name
MasonRAT
Signatures
- Family: NeptuneRAT, MasonRAT
NeptuneRAT aka MasonRAT is a trojan written in C#.
- Detects NeptuneRAT stealer 2 IoCs
- UAC bypass 3 TTPs 1 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 12 IoCs
- Adds Run key to start application 2 TTPs 1 IoCs
- Checks whether UAC is enabled 1 TTPs 1 IoCs
- Writes to the Master Boot Record (MBR) 1 TTPs 2 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.
- Direct Volume Access: Opens a physical disk for reading 1 TTPs 1 IoCs
Opens a raw handle to a physical disk, which bypasses file system access controls and is used for disk inspection, anti-VM checks and privilege checks.
- 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 6 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 8 IoCs
- Suspicious use of FindShellTrayWindow 1 IoCs
- Suspicious use of SetWindowsHookEx 1 IoCs
- Suspicious use of WriteProcessMemory 10 IoCs
- System policy modification 1 TTPs 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
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C:\Users\Admin\AppData\Local\Temp\MasonClient.exe"C:\Users\Admin\AppData\Local\Temp\MasonClient.exe"1⤵
- UAC bypass
- Checks computer location settings
- Adds Run key to start application
- Checks whether UAC is enabled
- Enumerates video capture drivers
- Reads the TCP/IP host and domain name from the registry
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
- System policy modification
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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\tmpD9D1.tmp.exe"C:\Users\Admin\AppData\Local\Temp\tmpD9D1.tmp.exe"2⤵
- Executes dropped EXE
- Writes to the Master Boot Record (MBR)
- Direct Volume Access: Opens a physical disk for reading
- System Location Discovery: System Language Discovery
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of FindShellTrayWindow
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
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C:\Users\Admin\AppData\Local\Temp\nasm.exe"nasm.exe" -f bin mbr_temp.asm -o mbr_temp.bin3⤵
- Executes dropped EXE
- System Location Discovery: System Language Discovery
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-
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C:\Users\Admin\AppData\Local\Temp\tmp7FD1.tmp.COM"C:\Users\Admin\AppData\Local\Temp\tmp7FD1.tmp.COM"2⤵
- Checks computer location settings
- Executes dropped EXE
- Suspicious use of WriteProcessMemory
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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
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C:\Windows\System32\MatrixMBR.exe"C:\Windows\System32\MatrixMBR.exe"4⤵
- Checks computer location settings
- Executes dropped EXE
- Suspicious use of WriteProcessMemory
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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
-
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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
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-
-
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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
-
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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
-
-
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C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
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C:\Windows\system32\AUDIODG.EXEC:\Windows\system32\AUDIODG.EXE 0x418 0x4a81⤵
- Suspicious use of AdjustPrivilegeToken
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C:\Users\Admin\AppData\Roaming\MasonClient.exeC:\Users\Admin\AppData\Roaming\MasonClient.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
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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
Abuse Elevation Control Mechanism
1Bypass User Account Control
1Boot or Logon Autostart Execution
1Registry Run Keys / Startup Folder
1Scheduled Task/Job
1Scheduled Task
1Defense Evasion
Abuse Elevation Control Mechanism
1Bypass User Account Control
1Direct Volume Access
1Impair Defenses
1Disable or Modify Tools
1Modify Registry
3Pre-OS Boot
1Bootkit
1Replay Monitor
Loading Replay Monitor...
Downloads
MasonClient.exe.log
GDI.exe
MBR.exe
MBR2.exe
TROLL2.exe
TROLL5.exe
mbr_temp.asm
mbr_temp.bin
nasm.exe
tmp7FD1.tmp.COM
tmpD9D1.tmp.exe
MasonClient.exe
MatrixMBR.exe
memory/452-93-0x0000000000840000-0x0000000000886000-memory.dmp
memory/740-111-0x0000000000CA0000-0x0000000000CA8000-memory.dmp
memory/1256-21-0x0000000004DB0000-0x0000000004DBA000-memory.dmp
memory/1256-20-0x0000000004D00000-0x0000000004D92000-memory.dmp
memory/1256-19-0x00000000053E0000-0x0000000005984000-memory.dmp
memory/1256-18-0x00000000001E0000-0x0000000000332000-memory.dmp
memory/2536-34-0x000000001B770000-0x000000001B7FE000-memory.dmp
memory/2536-35-0x000000001D330000-0x000000001D3BE000-memory.dmp
memory/2536-0-0x0000000000580000-0x0000000000592000-memory.dmp
memory/2536-6-0x0000000001480000-0x0000000001490000-memory.dmp
memory/2536-2-0x0000000001480000-0x0000000001490000-memory.dmp
memory/2876-79-0x00000000000E0000-0x0000000000198000-memory.dmp
memory/3500-94-0x0000000000400000-0x000000000041D000-memory.dmp
memory/4068-75-0x0000000000760000-0x000000000079A000-memory.dmp
memory/4824-30-0x0000000000400000-0x0000000000539000-memory.dmp
memory/4860-43-0x0000000002AE0000-0x0000000002BC4000-memory.dmp
memory/4860-42-0x00000000008E0000-0x00000000009CC000-memory.dmp