Email security Microsoft Defender for Office 365 mistakenly flags Google search links as malicious September 3, 2026 Share By SC Staff Microsoft is investigating an issue where its Defender for Office 365 security software is incorrectly identifying legitimate Google search links as malicious. Users attempting to access these links are encountering "Opening this website might not be safe" warnings, preventing them from proceeding. This problem is causing disruptions for users and may generate related alerts for IT administrators within Microsoft's security solutions, as reported by Bleeping Computer. The false positive is attributed to an inaccurate security classification within the Defender for Office 365 Safe Links feature. This feature is designed to protect users by rewriting URLs in emails and other Office 365 applications and verifying them at the time of click. However, in this instance, it is erroneously blocking access to valid Google search results. While Microsoft has not specified the number of affected customers or regions, it has categorized the issue as an advisory, suggesting a limited scope. This is not the first time Microsoft Defender has experienced such false positive incidents; similar issues have occurred in the past with Exchange Online, where legitimate emails were flagged as spam or phishing, or even quarantined. The company is actively working to correct the misclassification and restore normal functionality for affected users. Source: Bleeping Computer SC Staff Related Email security Brave browser introduces email aliases to enhance user privacy SC Staff August 31, 2026 This feature aims to shield users' primary email addresses from websites, while still ensuring that messages from these services are forwarded. Email security SVG attachments used in widespread phishing campaign SC Staff August 28, 2026 The attackers employed a broad, non-targeted approach, sending messages in waves and largely avoiding weekends. Email security Risk Advisory: Filtering Known-Bad Messages Does Not Prove Detection Readiness SC Media Editorial Intelligence, reviewed by Erika Carrara August 26, 2026 Block rate is not a proxy for detection coverage against these threats Related Events Cybercast Six pillars, zero gateways: The security model your SEG can’t deliver Thu Sep 24 Get daily email updates SC Media's daily must-read of the most current and pressing daily news Business Email By clicking the Subscribe button below, you agree to SC Media Terms of Use and Privacy Policy . Subscribe Related Terms Bring Your Own Device (BYOD) Eavesdropping Email Spoofing Internet Message Access Protocol (IMAP) Post Office Protocol, Version 3 (POP3) Spam Store-and-Forward You can skip this ad in 5 seconds