Listen to this Post
A critical vulnerability in WinRAR allows attackers to execute malware without triggering Windows security warnings. The exploit leverages a flaw in how WinRAR processes archived files, enabling malicious payloads to bypass standard detection mechanisms.
You Should Know:
1. Exploit Details:
- Attackers craft malicious RAR archives that evade signature-based detection.
- The exploit abuses WinRAR’s handling of specially formatted files.
2. Detection & Mitigation:
- Check WinRAR Version:
winrar /? | find "Version"
Ensure you’re using the latest patched version (6.23 or later).
Scan for Suspicious Archives:
Get-ChildItem -Path C:\ -Include .rar, .zip -Recurse | % { Write-Host "Checking $<em>"; Expand-Archive -Path $</em> -DestinationPath C:\Temp\Scan -Force }Disable WinRAR Integration (Temporary Fix):
reg add "HKCU\Software\WinRAR\Setup" /v "ShellIntegration" /t REG_DWORD /d 0 /f
3. Alternative Tools:
- Use 7-Zip or PeaZip until WinRAR releases a full patch.
What Undercode Say:
This exploit highlights the risks of relying on outdated compression tools. Always verify file integrity before extraction. For Linux users, leverage:
unrar l suspicious.rar List contents without extraction file suspicious.rar Check file type
Windows admins should enforce Group Policy to block execution from temp folders:
New-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\Explorer" -Name "DisableThumbnailCache" -Value 1 -PropertyType DWORD -Force
Monitor process creation via:
wmic process where "name='winrar.exe'" get CommandLine
Expected Output:
- Updated WinRAR installations.
- Logs of archive scans and process executions.
- Blocked unauthorized temp folder executions.
Reference: WinRAR Exploit
References:
Reported By: Sam Bent – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
