Full Report
A recently fixed WinRAR vulnerability tracked as CVE-2025-8088 was exploited as a zero-day in phishing attacks to install the RomCom malware. [...]
Analysis Summary
# Vulnerability: WinRAR Zero-Day RCE via Archive Handling
## CVE Details
- CVE ID: CVE-2025-8088
- CVSS Score: Information on the specific CVSS score is unavailable in the provided text, but the description implies a high severity as it leads to remote code execution when exploited in the wild.
- CWE: Not explicitly stated, description implies a weakness in archive processing leading to code execution.
## Affected Systems
- Products: WinRAR
- Versions: All versions prior to the patched release. (Specific vulnerable versions not listed, but users are advised to update).
- Configurations: Affects users handling malicious RAR archives distributed via phishing.
## Vulnerability Description
The vulnerability is a zero-day flaw in WinRAR's handling of archive files (RAR archives). When a user interacts with a specially crafted malicious RAR file, it can lead to the execution of arbitrary code on the victim's machine upon the next user login. This allows an attacker to achieve Remote Code Execution (RCE).
## Exploitation
- Status: **Exploited in the wild** (Used by the RomCom hacking group in spearphishing attacks).
- Complexity: Implied to be low/medium for successful exploitation via phishing, as it leverages the trust in opening archive attachments.
- Attack Vector: Network (via email attachment) leading to impact upon local execution/login.
## Impact
- Confidentiality: High (Implied, as the malware installs backdoors for persistent access).
- Integrity: High (Implied, due to installation of malware/backdoors).
- Availability: High (Implied, depending on the payload, but RCE grants full control).
## Remediation
### Patches
- Users must **manually download and install the latest version** of WinRAR from win-rar.com, as the software lacks an auto-update feature. Specific patch version numbers are not provided in the text.
### Workarounds
- Users should avoid opening suspicious RAR attachments received via email or other untrusted sources.
## Detection
- Indicators of Compromise: Installation of RomCom backdoors or associated malware following the opening of a suspicious RAR file.
- Detection methods and tools: ESET researchers are preparing a detailed report which should contain more specific detection methods. General detection focuses on monitoring execution of code stemming from WinRAR processes or persistence mechanisms established after archive opening.
## References
- Vendor Advisories: Users advised to update directly from win-rar.com.
- Relevant links - defanged:
- hxxps://www.bleepingcomputer.com/news/security/winrar-zero-day-flaw-exploited-by-romcom-hackers-in-phishing-attacks/
- hxxps://www.bleepingcomputer.com/news/security/firefox-and-windows-zero-days-exploited-by-russian-romcom-hackers/
- hxxps://www.bleepingcomputer.com/news/security/new-romcom-malware-variant-snipbot-spotted-in-data-theft-attacks/
- hxxps://www.bleepingcomputer.com/news/security/hacker-uses-new-rat-malware-in-cuba-ransomware-attacks/
- hxxps://www.bleepingcomputer.com/news/security/industrial-spy-data-extortion-market-gets-into-the-ransomware-game/