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[SITUATION] · [ACTIVE] · [TECHNOLOGY]

2 clusters · 9 sources · 3 days · First seen · Last updated

Microsoft Defender Google link false positive

Overview

Microsoft investigated a technical issue where its Microsoft Defender for Office 365 software incorrectly flagged legitimate Google search links as malicious. The error occurred within the Safe Links feature, which is intended to protect users from phishing by verifying URLs in real-time across email, Teams, and Office 365 applications.

Users encountered warnings stating that ‘opening this website might not be safe,’ or experienced immediate connection blocks and red warning screens. The incident caused a surge of automated security alerts across administration consoles and monitoring services like Microsoft Sentinel.

Microsoft identified the cause as an internal inaccuracy in its threat classification process, specifically a reputation reading error within its own security infrastructure. The company confirmed the event was a large-scale false positive and that there was no actual threat from Google servers or any targeted cyberattacks. The issue was cataloged internally under technical reference MO1465962.

Entities

Google · Microsoft · Microsoft Defender · Office 365 · Windows

Timeline

  1. 5 days ago

    [TECHNOLOGY] 2 sources
    Microsoft Defender incorrectly flags Google search results as dangerous

    Microsoft Defender incorrectly flagged Google search results as dangerous, causing access blocks for Windows and Office 365 users due to a threat classification error.

  2. 8 days ago

    [TECHNOLOGY] 7 sources
    Microsoft Defender incorrectly flags Google links as malicious

    Microsoft Defender for Office 365 incorrectly flagged legitimate Google search links as malicious, triggering security warnings for users before the issue was resolved.

Sources

actusmartphone.fr · borncity.com · ipadizate.es · movilzona.es · pplware.sapo.pt · redeszone.net · sapo.pt · tecnobreak.com · xataka.com.mx