GhostLock Attack Disrupts Windows File Systems Without Encryption

• •GhostLock exploits a Windows API flaw to lock files without encryption.
• •The attack can disrupt enterprise file systems at scale, affecting numerous organizations.
• •No specific CVEs are reported yet, but the cybersecurity community is on high alert.

The GhostLock attack, disclosed on May 11, 2026, exploits a flaw in the Windows CreateFileW API, allowing attackers to lock SMB files without writing encrypted data to disk. This fundamentally challenges the traditional ransomware model, which relies on data encryption for disruption. Organizations relying on Windows file-sharing are particularly vulnerable, as the attack can paralyze enterprise file systems at scale. Discovered by Kim Dvash, this technique has raised alarms in the cybersecurity community, prompting urgent discussions about defense strategies. The attack's implications could affect millions of users and businesses globally, as it bypasses conventional ransomware detection methods. Currently, no specific CVEs have been disclosed for this attack, but the security community is on high alert for potential exploitation. Security professionals are advised to monitor for unusual file access patterns and implement additional safeguards.