Critical Directory Traversal Flaw Patched: The WinRAR Silent Malware Threat—Is Your Company Secure?

More than 500 million people worldwide utilize WinRAR, which had a serious vulnerability (CVE202436052) that allowed hackers to covertly install malware while victims opened seemingly innocuous archive files. Through a deceptively simple attack vector, this directory traversal vulnerability, now fixed in version 7.00, put firms at serious risk.

How the Exploit Worked

• The Creation of a Malicious Archive

                Hackers created ZIP/RAR files with altered paths, such as .... WindowsStartupmalware. exe.

• Quiet Installation of Malware

                Files skipped security checks and installed themselves in system directories when retrieved.

• Mechanisms of persistence

               Malware that self-starts upon bootup, allowing for:

• Remote system management

               The stealing of data

• Ransomware implementation

Actual World Impact: The BlackBasta ransomware was delivered to an accounting business's network by attackers who pretended to be shipping invoices, resulting in more than $200,000 in damages.

Why This Vulnerability Was Critical

• No User Warnings: Victims saw only legitimate-looking extracted files.

• Evasion Capabilities: Bypassed 70% of endpoint security tools (Black Hat testing).

• Supply Chain Risks: Compromised contractors transmitted infected archives to clients.

Industries at High Risk

• Finance: Fake "transaction archive" attacks

• Legal: Malicious "case file" bundles

• Healthcare: Infected medical record archives

5 Urgent Mitigation Steps

• Update Immediately

               Upgrade to WinRAR 7.00+ (verify via Help > About).

• Restrict Archive Software

               Block non-essential tools like WinRAR on corporate endpoints.

• Sandbox All Archives

                Use virtual environments to inspect suspicious ZIP/RAR files.

• Enable File Extension Visibility

               Ensure Windows shows full extensions (e.g., .exe not hidden).

• Scan with Heuristic Tools

                Deploy next-gen antivirus with behavior-based detection.

The Bigger Picture: Software Supply Chain Threats

This incident highlights a dangerous trend:

• 62% of businesses use outdated software with known vulnerabilities (SANS 2025)

• Archive files are the #2 malware delivery vector (after email)

• State-sponsored groups increasingly exploit "trusted" tools

Bayon Technologies Group: Secure Your Systems Against Silent Threats

Proactive defense is necessary against legacy software vulnerabilities, such as WinRAR's vulnerability. We provide:

✅ Automate Patch Management: Make sure all endpoints receive important updates.

✅ Advanced Endpoint Protection: Use AI-powered EDR to stop file-based malware.

✅ Vulnerability Scanning: Instantaneously identify obsolete software.

✅ Cyber-Drills for Employees: Model phishing assaults using archives.

Don't let a compressed file compress your business operations.