neptunerat | 0c133b862b888624ed150416ff508db4fd7ca456271140f5c4c6f7b43cdb7e27

Analysis

user interaction
yes
max time kernel
99s
max time network
113s
platform
windows10-ltsc_2021_x64
resource
win10ltsc2021-20260513-en
resource tags

arch:x64arch:x86image:win10ltsc2021-20260513-enlocale:en-usos:windows10-ltsc_2021-x64systemwindows
submitted
02/08/2026, 05:11

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Reason

Machine shutdown

General

Target
MasonClient.exe
Size 48KB
Sample260802-fvd2vstsfz
SHA256 0c133b862b888624ed150416ff508db4fd7ca456271140f5c4c6f7b43cdb7e27
MD5 6a945e2e26dbc932eda6191d36eab1fc
SHA1 66a048dd022749b7913be009d44982d5ba962cca
SHA512 28a3908f2ba59f15e43dd478b6224f33f32ce2b0ea866e82892435eac6235124a9b7e5571a3ff3fe7a0cf23dd7fa7b2b0c4357690e512b22bf17b46a11914f04
SSDEEP 768:X5rAl238UNRgvXqbbAtf+2+gQN/zohLOisOYs:XB7RavqbbAtG21OiVYs
TLSH
T1D723C64DBBE50129D5BE6AB12D736209C3B079D39507C60FACD406CB2B27B984690EF7
MD5 SHA1 SHA512 SSDEEP TLSH

Score

10^/10

bootkit defense_evasion discovery execution neptunerat persistence ransomware trojan

Malware Config

Extracted

Family

neptunerat

24.tcp.cpolar.top:10236

Attributes

filename
USB.exe
group
MasonGroup
key
uEZZrxy1VzemmhEt
rat_name
MasonRAT

Signatures

Family: NeptuneRAT, MasonRAT
NeptuneRAT aka MasonRAT is a trojan written in C#.
trojan neptunerat

Detects NeptuneRAT stealer 2 IoCs

resource	yara_rule
behavioral2/memory/3016-0-0x0000000000E00000-0x0000000000E12000-memory.dmp	family_neptunerat
behavioral2/files/0x00050000000273ac-2.dat	family_neptunerat

Disables Task Manager via registry modification
defense_evasion

Checks computer location settings 2 TTPs 4 IoCs

Looks up country code configured in the registry, likely geofence.

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-1741132852-2793423776-1557670484-1000\Control Panel\International\Geo\Nation	MBR2.exe
Key value queried	\REGISTRY\USER\S-1-5-21-1741132852-2793423776-1557670484-1000\Control Panel\International\Geo\Nation	MatrixMBR.exe
Key value queried	\REGISTRY\USER\S-1-5-21-1741132852-2793423776-1557670484-1000\Control Panel\International\Geo\Nation	MasonClient.exe
Key value queried	\REGISTRY\USER\S-1-5-21-1741132852-2793423776-1557670484-1000\Control Panel\International\Geo\Nation	tmp4378.tmp.exe

Executes dropped EXE 10 IoCs

pid	Process
1792	MasonClient.exe
3532	MasonClient.exe
3512	tmp4378.tmp.exe
1060	MBR2.exe
4660	TROLL5.exe
3104	TROLL2.exe
4756	MasonClient.exe
3892	MatrixMBR.exe
4112	GDI.exe
5064	MBR.exe

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.

bootkit persistence

Bootkit

T1542.003

description	ioc	Process
File opened for modification	\??\PhysicalDrive0	MBR.exe

Drops file in System32 directory 2 IoCs

description	ioc	Process
File created	C:\Windows\System32\MatrixMBR.exe	MBR2.exe
File opened for modification	C:\Windows\System32\MatrixMBR.exe	MBR2.exe

Sets desktop wallpaper using registry 2 TTPs 1 IoCs

ransomware

Defacement

T1491

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-1741132852-2793423776-1557670484-1000\Control Panel\Desktop\Wallpaper = "C:\\Users\\Admin\\AppData\\Local\\Temp\\img.Bmp"	MasonClient.exe

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

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.

discovery

System Language Discovery

T1614.001

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	MBR.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	GDI.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	TROLL5.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	TROLL2.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 1 IoCs

Schtasks is often used by malware for persistence or to perform post-infection execution.

persistence execution

Scheduled Task

T1053.005

pid	Process
4100	schtasks.exe

Suspicious use of AdjustPrivilegeToken 5 IoCs

description	pid	Process
Token: SeDebugPrivilege	3016	MasonClient.exe
Token: SeDebugPrivilege	1792	MasonClient.exe
Token: SeDebugPrivilege	3532	MasonClient.exe
Token: SeDebugPrivilege	4756	MasonClient.exe
Token: SeShutdownPrivilege	5064	MBR.exe

Suspicious use of WriteProcessMemory 8 IoCs

description	pid	Process	procid_target
PID 3016 wrote to memory of 4100	3016	MasonClient.exe	84
PID 3016 wrote to memory of 3512	3016	MasonClient.exe	98
PID 3512 wrote to memory of 1060	3512	tmp4378.tmp.exe	99
PID 3512 wrote to memory of 4660	3512	tmp4378.tmp.exe	100
PID 3512 wrote to memory of 3104	3512	tmp4378.tmp.exe	101
PID 1060 wrote to memory of 3892	1060	MBR2.exe	104
PID 3892 wrote to memory of 4112	3892	MatrixMBR.exe	106
PID 3892 wrote to memory of 5064	3892	MatrixMBR.exe	107

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.
persistence

Query Registry
T1012

C:\Users\Admin\AppData\Local\Temp\MasonClient.exe
"C:\Users\Admin\AppData\Local\Temp\MasonClient.exe"
1⤵
- Checks computer location settings
- Sets desktop wallpaper using registry
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:3016
- 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:4100
- C:\Users\Admin\AppData\Local\Temp\tmp4378.tmp.exe
  "C:\Users\Admin\AppData\Local\Temp\tmp4378.tmp.exe"
  2⤵
  - Checks computer location settings
  - Executes dropped EXE
  - Suspicious use of WriteProcessMemory
  PID:3512
- - 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
    PID:1060
  - - C:\Windows\System32\MatrixMBR.exe
      "C:\Windows\System32\MatrixMBR.exe"
      4⤵
      Checks computer location settings
      Executes dropped EXE
      Suspicious use of WriteProcessMemory
      PID:3892
    - - 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
        
        PID:4112
    - - 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
        
        PID:5064
- - 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
    PID:4660
- - 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
    PID:3104

C:\Users\Admin\AppData\Roaming\MasonClient.exe
C:\Users\Admin\AppData\Roaming\MasonClient.exe
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:1792

C:\Users\Admin\AppData\Roaming\MasonClient.exe
"C:\Users\Admin\AppData\Roaming\MasonClient.exe"
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:3532

C:\Windows\system32\AUDIODG.EXE
C:\Windows\system32\AUDIODG.EXE 0x454 0x48c
1⤵
PID:2592

C:\Users\Admin\AppData\Roaming\MasonClient.exe
"C:\Users\Admin\AppData\Roaming\MasonClient.exe"
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:4756

Network

MITRE ATT&CK Enterprise v16

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Persistence

Pre-OS Boot

T1542

Bootkit

T1542.003

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Privilege Escalation

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Defense Evasion

Modify Registry

T1112

Pre-OS Boot

T1542

Bootkit

T1542.003

Credential Access

Discovery

Query Registry

T1012

System Information Discovery

T1082

System Location Discovery

T1614

System Language Discovery

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Defacement

T1491

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Downloads

MasonClient.exe.log

Path C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\MasonClient.exe.log
Size 654B
SHA256 d39a78fabca39532fcb85ce908781a75132e1bd01cc50a3b290dd87127837d63
MD5 11c6e74f0561678d2cf7fc075a6cc00c
SHA1 535ee79ba978554abcb98c566235805e7ea18490
SHA512 32c63d67bf512b42e7f57f71287b354200126cb417ef9d869c72e0b9388a7c2f5e3b61f303f1353baa1bf482d0f17e06e23c9f50b2f1babd4d958b6da19c40b0
TLSH
T136F0783432A2E1D5C9127F111C1D298452AF8386B6A0AF1C7A68935DD8261376F313F3
MD5 SHA1 SHA512 TLSH

Submit Download

GDI.exe

Path C:\Users\Admin\AppData\Local\Temp\GDI.exe
Size 11KB
SHA256 e153def894c867923dd56a7025b7b0b7bd3ee37c801a5957201d39f999bb28bf
MD5 c08ae6d9c6ecd7e13f827bf68767785f
SHA1 e71c2ec8d00c1e82b8b07baee0688b0a28604454
SHA512 c28bbe8abc66ad2433e5a3b93a4601b28225e86cb4bff077fd3224adfa63164bebfa3002a42b1cb4cb3c7ccad0208f8b143b8a17099bea04fcb964e667c7a1c0
SSDEEP 192:99qzCdTRiOurQItQ6YTkMfTiC96Tp80/Yc/75e:PXdTROQItQTTka2O6Tp3/Yc/g
TLSH
T1B432191197D08276ED320AB278A35742CB77EB57D967DABE348C912BBF732014293361
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

MBR.exe

Path C:\Users\Admin\AppData\Local\Temp\MBR.exe
Size 93KB
SHA256 acddde9514e3b9d5c40b3d1750af5f4187c99f8987b027d6da44fb6bcf79b3ca
MD5 d2fc66cf781a2497fceb4041a93cc676
SHA1 480b1aa31b0b31fc0e0833afbba06533ab9a90ee
SHA512 6c4cb42f786301be7614d4cb0b32601fea151351b0877e2371632435eb2c54bd4cd04d6b23bf4f49017ccaf679331162aac7329a1ed2409e3c2e02d0326e3487
SSDEEP 1536:CmwoXyoci5SjY3SaRO7IPqifrJxdhGZCJjmGasWhQcdQ5/hO2oFaLJ:Tv5MYRIMPqiTJx+ZqreRQ5/hXoM9
TLSH
T10A936C43B5D28CB2E5B21D311875CAA15A2FB9214E348E6B6794137E1F340D09E36FB7
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

MBR2.exe

Path C:\Users\Admin\AppData\Local\Temp\MBR2.exe
Size 205KB
SHA256 c22e2419f04fe03a92255a139ca8814697962e86d191a1d4171788fd0c903f68
MD5 3dc0e225f886bae3b655cd9d738ed32f
SHA1 abda127fd477bd9d051cd57b16ac13f44030a9ae
SHA512 c8a6c0bfa96defde6f83d847583ff2ec065a43f80f9886259a2d1fe7df306ef6ed7aeed61b7dcf0bdc111fc67419eb66cf1ca44e831711dd4ea7d25ed9aed09b
SSDEEP 3072:VQKrqi3qqKcjzksuicc/9Ic9hwBjQV8xWegUqijR4uTkEJxIiLt2p/YkMhapu4n4:Vruc/iuwBMV8x5gUqMR4aMiLcpj84
TLSH
T1D92423001754132EFB59C0F6019712B381EBD3AE9E1B9489F3F9921BDB6B10ED91747A
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

TROLL2.exe

Path C:\Users\Admin\AppData\Local\Temp\TROLL2.exe
Size 105KB
SHA256 dcdf5140bc51db27f3aec80ae9a66a57aad446a2522904d288770e8d8cde8cee
MD5 52a2a5517deb1a06896891a35299ce20
SHA1 badcbdfef312bd71de997a7416ee20cee5d66af6
SHA512 7cb0de412c0508f5af522aeaf3731dda418f72f7cae8dd3f21b34d5cdbc08f9dea8699d59878610496c68d687227a0269739221490d70d03b8e4b84dfd29d5f1
SSDEEP 1536:A85iT6EcrYTyyAmOvu3yUyJCbT4UK7BIR:IGEcxyAF64A
TLSH
T1D6B3F6D7BE8AADA3F925133989F98319033DF7C01B828B171D31993A17176A17FC5246
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

TROLL5.exe

Path C:\Users\Admin\AppData\Local\Temp\TROLL5.exe
Size 712KB
SHA256 79f00c7dab0891824136539fabd542c74e26cbed94b9add3f1aa7f793d653de6
MD5 542a4e400ff233b21a1a3c27751ac783
SHA1 000a67f00b0003531d65a6ed6f16488ae5dcd0fe
SHA512 8335118ca0c268635d9495b331fb65800a32a0631f132cd34ce84ca3b523d0a9e23eee6d76539d0c81d86fda534da56c936914012d8bad35040b15cc8caaf645
SSDEEP 12288:cF04yK+m1Vd5IfbJQWYzBVXqKWOF+LmguP/WMYZCubHKG91MiYwd:Z4yedWfEHnWbLunWMYUaHzLY2
TLSH
T1BDF423738484A51CD6EFCE33A0F1FC3463BAFE2761198C112294EDD46AA715097CBB65
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

tmp4378.tmp.exe

Path C:\Users\Admin\AppData\Local\Temp\tmp4378.tmp.exe
Size 921KB
SHA256 deaf30953149d0bef45a11bd89f4ef69f77115e50380c7ef3607c37ff4f40a1d
MD5 03c3e9290329eec39c6543006f9ac9f1
SHA1 78e676fc850fb5d4e1c75b813f15b841fdf7705d
SHA512 b2c5b1b060a0349bc92cc5a8b286f149b5cf6b40264e7b613b76c911e4acc6352ed0fdd9d945fae9c025963cae02f3f2cbef8a62bff844764a66481119c6321d
SSDEEP 24576:QCFZOZHLhrN+f4SULfWyBPzB8JAk4cQATg:1F+LL+fIWybB8
TLSH
T13B15239832772A1FCCE72737E5E739A463AE323D0937229D04A5F37D1E415C05726AA2
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

MasonClient.exe

Path C:\Users\Admin\AppData\Roaming\MasonClient.exe
Size 48KB
SHA256 0c133b862b888624ed150416ff508db4fd7ca456271140f5c4c6f7b43cdb7e27
MD5 6a945e2e26dbc932eda6191d36eab1fc
SHA1 66a048dd022749b7913be009d44982d5ba962cca
SHA512 28a3908f2ba59f15e43dd478b6224f33f32ce2b0ea866e82892435eac6235124a9b7e5571a3ff3fe7a0cf23dd7fa7b2b0c4357690e512b22bf17b46a11914f04
SSDEEP 768:X5rAl238UNRgvXqbbAtf+2+gQN/zohLOisOYs:XB7RavqbbAtG21OiVYs
TLSH
T1D723C64DBBE50129D5BE6AB12D736209C3B079D39507C60FACD406CB2B27B984690EF7
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

MatrixMBR.exe

Path C:\Windows\System32\MatrixMBR.exe
Size 250KB
SHA256 339fe94164952a8454e6ec5fc75e2c38baade2c14b231e47bf41989ffbb55ee4
MD5 24c441662c09b94e14a4096a8e59c316
SHA1 11576cad137bd8ed76efecd711c0390fe5c85292
SHA512 7f6ca1366733c5fb4925001c0846510732031a9e5f1b16291ff596187c20a88f41193389cedcb73e3928c318fc972be4f03e3cb71f1487c34642897ff9a2b590
SSDEEP 6144:XGaiVa9WL/GgkszuMO1yV8xTgUqMRQaMiBcxj8:Waisszux1yGRLHBo
TLSH
T1FD4402053F44A465D3689BB08AF3E2A782B8FD396C02D95BFD84775F2E37D0E9801265
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

memory/1060-57-0x00000000005D0000-0x000000000060A000-memory.dmp

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memory/3016-7-0x0000000002EC0000-0x0000000002EC8000-memory.dmp

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memory/3016-0-0x0000000000E00000-0x0000000000E12000-memory.dmp

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memory/3016-4-0x0000000002ED0000-0x0000000002EE0000-memory.dmp

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memory/3016-1-0x0000000002ED0000-0x0000000002EE0000-memory.dmp

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memory/3104-76-0x0000000000400000-0x000000000041D000-memory.dmp

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memory/3512-24-0x000000001B000000-0x000000001B0E4000-memory.dmp

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memory/3512-23-0x0000000000160000-0x000000000024C000-memory.dmp

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memory/3892-91-0x0000000000360000-0x00000000003A6000-memory.dmp

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memory/4112-118-0x0000000000010000-0x0000000000018000-memory.dmp

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memory/4660-69-0x0000000000CB0000-0x0000000000D68000-memory.dmp

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memory/4660-70-0x0000000005D80000-0x0000000006326000-memory.dmp

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memory/4660-71-0x00000000057D0000-0x0000000005862000-memory.dmp

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memory/4660-72-0x0000000005750000-0x000000000575A000-memory.dmp

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Analysis

Sharing

Errors

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v16

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