neptunerat | 27dac225328b8f0f8717dfe2acffa4cd8b012e9ceaaf7259ff29fce8ea07cdf5

Analysis

user interaction
yes
max time kernel
149s
max time network
151s
platform
windows10-2004_x64
resource
win10v2004-20260911-en
resource tags

arch:x64arch:x86image:win10v2004-20260911-enlocale:en-usos:windows10-2004-x64systemwindows
submitted
27/09/2026, 05:16

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General

Target
MasonClient.exe
Size 50KB
Sample260927-fx9xbazbme
SHA256 27dac225328b8f0f8717dfe2acffa4cd8b012e9ceaaf7259ff29fce8ea07cdf5
MD5 b80fce829addb197edc2f132dfef7f14
SHA1 9e6ae115369922ce4eb40d1de3fd12362fe9aec1
SHA512 7322b7b64eac8252f1fc14a2f80d9826335ecfbc69cc5b5d2f9fb54a0f709f068fca020b9d1e0f6e47a0ee55632cca22bf8becc2e75b7b69e8c66e643ba8acb2
SSDEEP 768:aTyznAgXApoz2lSexephUx2bYyxv8J3DNm8xhBOns1:aTimFrmBbY6vMxDOs1
TLSH
T1FE33E84CFBE44129D5BE6AF16D73A20987B079939517C61F6CC402CB2B6B7884690AF3
MD5 SHA1 SHA512 SSDEEP TLSH

Score

10^/10

discovery execution neptunerat persistence trojan

Malware Config

Extracted

Family

neptunerat

nl.portbuddy.tech:40389

Attributes

filename
USB.exe
group
MasonGroup
key
N118d1bgVbAMPHpa
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
behavioral1/memory/1640-0-0x00000000004D0000-0x00000000004E2000-memory.dmp	family_neptunerat
behavioral1/files/0x00120000000241dd-3.dat	family_neptunerat

Checks computer location settings 2 TTPs 1 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-1-5-21-2101206053-1414382737-268919432-1000\Control Panel\International\Geo\Nation	MasonClient.exe

Executes dropped EXE 3 IoCs

pid	Process
2232	MasonClient.exe
4056	MasonClient.exe
4592	MasonClient.exe

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

System Information Discovery
T1082

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.

discovery

System Network Configuration Discovery

T1016

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Hostname	MasonClient.exe
Key value queried	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Domain	MasonClient.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
3528	schtasks.exe

Suspicious use of AdjustPrivilegeToken 4 IoCs

description	pid	Process
Token: SeDebugPrivilege	1640	MasonClient.exe
Token: SeDebugPrivilege	2232	MasonClient.exe
Token: SeDebugPrivilege	4056	MasonClient.exe
Token: SeDebugPrivilege	4592	MasonClient.exe

Suspicious use of WriteProcessMemory 1 IoCs

description	pid	Process	procid_target
PID 1640 wrote to memory of 3528	1640	MasonClient.exe	85

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
- Reads the TCP/IP host and domain name from the registry
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1640
- 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:3528

C:\Users\Admin\AppData\Roaming\MasonClient.exe
C:\Users\Admin\AppData\Roaming\MasonClient.exe
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:2232

C:\Users\Admin\AppData\Roaming\MasonClient.exe
C:\Users\Admin\AppData\Roaming\MasonClient.exe
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:4056

C:\Users\Admin\AppData\Roaming\MasonClient.exe
C:\Users\Admin\AppData\Roaming\MasonClient.exe
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:4592

Network

MITRE ATT&CK Enterprise v16

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Persistence

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Privilege Escalation

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Defense Evasion

Credential Access

Discovery

Query Registry

T1012

System Information Discovery

T1082

System Network Configuration Discovery

T1016

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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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 e1b91642d85d98124a6a31f710e137ab7fd90dec30e74a05ab7fcf3b7887dced
MD5 2ff39f6c7249774be85fd60a8f9a245e
SHA1 684ff36b31aedc1e587c8496c02722c6698c1c4e
SHA512 1d7e8b92ef4afd463d62cfa7e8b9d1799db5bf2a263d3cd7840df2e0a1323d24eb595b5f8eb615c6cb15f9e3a7b4fc99f8dd6a3d34479222e966ec708998aed1
TLSH
T1D9F0DD242221E1C489127F111C0D2A4452BF4797B760EE0C7554529FD8312275F203E7
MD5 SHA1 SHA512 TLSH

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MasonClient.exe

Path C:\Users\Admin\AppData\Roaming\MasonClient.exe
Size 50KB
SHA256 27dac225328b8f0f8717dfe2acffa4cd8b012e9ceaaf7259ff29fce8ea07cdf5
MD5 b80fce829addb197edc2f132dfef7f14
SHA1 9e6ae115369922ce4eb40d1de3fd12362fe9aec1
SHA512 7322b7b64eac8252f1fc14a2f80d9826335ecfbc69cc5b5d2f9fb54a0f709f068fca020b9d1e0f6e47a0ee55632cca22bf8becc2e75b7b69e8c66e643ba8acb2
SSDEEP 768:aTyznAgXApoz2lSexephUx2bYyxv8J3DNm8xhBOns1:aTimFrmBbY6vMxDOs1
TLSH
T1FE33E84CFBE44129D5BE6AF16D73A20987B079939517C61F6CC402CB2B6B7884690AF3
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

memory/1640-0-0x00000000004D0000-0x00000000004E2000-memory.dmp

Download

memory/1640-2-0x0000000000D10000-0x0000000000D20000-memory.dmp

Download

memory/1640-6-0x0000000000D10000-0x0000000000D20000-memory.dmp

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v16

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Downloads