Microsoft Defender for Office 365 Plan 1 will enable users to report suspicious Teams messages as security risks or false positives starting late February 2026. Reports appear in the Defender portal, the feature is opt-in, and admins can configure settings to enhance phishing and malware detection in Teams.
Day in brief
Microsoft Defender Antivirus: Change to exclusion storage when using MDE security settings management leads 9 Defender updates
13 February 2026 recorded 7 updated Microsoft Defender documentation changes and 2 relevant Message Center announcements. The most active areas were Office 365, Defender XDR.
- Microsoft Defender Antivirus: Change to exclusion storage when using MDE security settings management
Defender XDR · Endpoint protectionStarting March 2026, Microsoft Defender Antivirus with MDE security settings will stop storing readable exclusions in the local registry. Organizations must use PowerShell cmdlets like Get-MpPreference to retrieve settings. Registry-based monitoring will no longer work; update scripts and notify teams accordingly.
- Microsoft Defender for Office 365: Enable users to report suspicious Teams messages in Plan 1
Defender XDR · Architecture and deploymentMicrosoft Defender for Office 365 Plan 1 will enable users to report suspicious Teams messages as security risks or false positives starting late February 2026. Reports appear in the Defender portal, the feature is opt-in, and admins can configure settings to enhance phishing and malware detection in Teams.
- Quarantine About
Office 365 · Email and collaborationUpdated Microsoft Defender documentation in defender-office-365/quarantine-about.md.
- Quarantine Quarantine NotificationsOffice 365 · Email and collaboration
Updated Microsoft Defender documentation in defender-office-365/quarantine-quarantine-notifications.md.
- Secure By DefaultOffice 365 · Email and collaboration
Updated Microsoft Defender documentation in defender-office-365/secure-by-default.md.
This period briefing was assembled from the tracked Microsoft Learn and Message Center changes.
9 updates
Microsoft Defender XDR
2 updatesStarting March 2026, Microsoft Defender Antivirus with MDE security settings will stop storing readable exclusions in the local registry. Organizations must use PowerShell cmdlets like Get-MpPreference to retrieve settings. Registry-based monitoring will no longer work; update scripts and notify teams accordingly.
Microsoft Defender for Office 365
7 updatesQuarantine About
UpdatedUpdated Microsoft Defender documentation in defender-office-365/quarantine-about.md.
Updated Microsoft Defender documentation in defender-office-365/quarantine-quarantine-notifications.md.
Secure By Default
UpdatedUpdated Microsoft Defender documentation in defender-office-365/secure-by-default.md.
Zero Hour Auto Purge
UpdatedUpdated Microsoft Defender documentation in defender-office-365/zero-hour-auto-purge.md.
Updated Microsoft Defender documentation in defender-office-365/anti-malware-policies-configure.md.
Anti Spam Policies Configure
UpdatedUpdated Microsoft Defender documentation in defender-office-365/anti-spam-policies-configure.md.
Anti Spam Protection About
UpdatedUpdated Microsoft Defender documentation in defender-office-365/anti-spam-protection-about.md.