Microsoft patches actively exploited zero-day Outlook NTLM hash theft vulnerability
What happened.Microsoft addressed an actively exploited zero-day spoofing vulnerability in Outlook during its monthly security update cycle.
Why it matters.Desktop email clients serve as standard workspace hubs across corporate environments. When opening a file triggers silent background authentication without user consent, attackers harvest password hashes to access internal corporate networks. System administrators must deploy monthly Office patches across all enterprise endpoints. Security operations teams should block outbound SMB port 445 traffic at the network perimeter.