Microsoft Blocks File Explorer Previews to Stop Hash Leak Attacks
Microsoft is rolling out a security update that automatically disables File Explorer previews for files downloaded from the internet. The change addresses a vulnerability where previewing HTML-tagged files could leak NTLM authentication hashes. Users must now manually unblock files through Properties to restore preview functionality.
Microsoft is taking a more aggressive stance against a sneaky credential-stealing technique by disabling a convenient Windows feature that many users take for granted. According to security reports, the latest Windows updates now automatically block File Explorer previews for files downloaded from the internet, closing what analysts describe as a significant hash leakage vulnerability.