neptunerat | b9cdd113799ba3b6f22bc5ed593a71a61f37429b14af020a2acbed2eab6686a8

Analysis

max time kernel
149s
max time network
142s
platform
windows10-ltsc_2021_x64
resource
win10ltsc2021-20260911-en
resource tags

arch:x64arch:x86image:win10ltsc2021-20260911-enlocale:en-usos:windows10-ltsc_2021-x64systemwindows
submitted
23/09/2026, 23:38

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General

Target
MasonClient.exe
Size 48KB
Sample260923-3m4zmsgc95
SHA256 b9cdd113799ba3b6f22bc5ed593a71a61f37429b14af020a2acbed2eab6686a8
MD5 e85edb5b4419933ff4fc1063cb8ed87d
SHA1 5beb0a7e267da66c8648dd8f69e4b845a7eb12e5
SHA512 2202baae2c33e05f13c59c916b0de348e23dd5017f62c8ed6637fa476689c9d2e4b8a7a885ffb74f7e61847dd21f2aaa7f5d6221ae49b3ddaa9566554b4657da
SSDEEP 768:HoqBK+AEqgvHyzw2Prth9sLZZI4bYlnggUNcgGhLOHOYD:HoqBxLvEw2BcZbYlnBld1OuYD
TLSH
T1A123C48DBBE40129D5BE5BF16D73A209C3B079939506C60FACD402CB2B677984691EF3
MD5 SHA1 SHA512 SSDEEP TLSH

Score

10^/10

execution neptunerat persistence trojan

Malware Config

Extracted

Family

neptunerat

h2ackercypranos-49474.portmap.host:49474

Attributes

filename
USB.exe
group
MasonGroup
key
OWKlVlNZmydAbDUL
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/2460-0-0x0000000000280000-0x0000000000292000-memory.dmp	family_neptunerat
behavioral2/files/0x001f00000002735a-2.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-1-5-21-3353145205-3618084634-580274525-1000\Control Panel\International\Geo\Nation	MasonClient.exe

Executes dropped EXE 4 IoCs

pid	Process
5056	MasonClient.exe
5504	MasonClient.exe
4736	MasonClient.exe
3968	MasonClient.exe

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

System Information Discovery
T1082

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
4924	schtasks.exe

Suspicious use of AdjustPrivilegeToken 5 IoCs

description	pid	Process
Token: SeDebugPrivilege	2460	MasonClient.exe
Token: SeDebugPrivilege	5056	MasonClient.exe
Token: SeDebugPrivilege	5504	MasonClient.exe
Token: SeDebugPrivilege	4736	MasonClient.exe
Token: SeDebugPrivilege	3968	MasonClient.exe

Suspicious use of WriteProcessMemory 1 IoCs

description	pid	Process	procid_target
PID 2460 wrote to memory of 4924	2460	MasonClient.exe	83

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
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2460
- 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:4924

C:\Users\Admin\AppData\Roaming\MasonClient.exe
C:\Users\Admin\AppData\Roaming\MasonClient.exe
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:5056

C:\Users\Admin\AppData\Roaming\MasonClient.exe
"C:\Users\Admin\AppData\Roaming\MasonClient.exe"
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:5504

C:\Users\Admin\AppData\Roaming\MasonClient.exe
"C:\Users\Admin\AppData\Roaming\MasonClient.exe"
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:4736

C:\Users\Admin\AppData\Roaming\MasonClient.exe
"C:\Users\Admin\AppData\Roaming\MasonClient.exe"
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:3968

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

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 d39a78fabca39532fcb85ce908781a75132e1bd01cc50a3b290dd87127837d63
MD5 11c6e74f0561678d2cf7fc075a6cc00c
SHA1 535ee79ba978554abcb98c566235805e7ea18490
SHA512 32c63d67bf512b42e7f57f71287b354200126cb417ef9d869c72e0b9388a7c2f5e3b61f303f1353baa1bf482d0f17e06e23c9f50b2f1babd4d958b6da19c40b0
TLSH
T136F0783432A2E1D5C9127F111C1D298452AF8386B6A0AF1C7A68935DD8261376F313F3
MD5 SHA1 SHA512 TLSH

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MasonClient.exe

Path C:\Users\Admin\AppData\Roaming\MasonClient.exe
Size 48KB
SHA256 b9cdd113799ba3b6f22bc5ed593a71a61f37429b14af020a2acbed2eab6686a8
MD5 e85edb5b4419933ff4fc1063cb8ed87d
SHA1 5beb0a7e267da66c8648dd8f69e4b845a7eb12e5
SHA512 2202baae2c33e05f13c59c916b0de348e23dd5017f62c8ed6637fa476689c9d2e4b8a7a885ffb74f7e61847dd21f2aaa7f5d6221ae49b3ddaa9566554b4657da
SSDEEP 768:HoqBK+AEqgvHyzw2Prth9sLZZI4bYlnggUNcgGhLOHOYD:HoqBxLvEw2BcZbYlnBld1OuYD
TLSH
T1A123C48DBBE40129D5BE5BF16D73A209C3B079939506C60FACD402CB2B677984691EF3
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

memory/2460-0-0x0000000000280000-0x0000000000292000-memory.dmp

Download

memory/2460-1-0x000000001AFE0000-0x000000001AFF0000-memory.dmp

Download

memory/2460-6-0x000000001AFE0000-0x000000001AFF0000-memory.dmp

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Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v16

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Downloads