Microsoft Defender XDR will add an AI-powered Email summary via Security Copilot on the Email entity page, launching in public preview mid-April 2026 and generally available by mid-May 2026. It provides concise threat insights, timeline analysis, URL and attachment assessments, requiring Security Copilot access and SCUs.
Day in brief
Migrating from a non-Microsoft HIPS to attack surface reduction rules leads 18 Defender updates
2 April 2026 recorded 17 updated Microsoft Defender documentation changes and 1 relevant Message Center announcement. The most active areas were Office 365, Endpoint, Defender XDR.
- Migrating from a non-Microsoft HIPS to attack surface reduction rules
Endpoint · Vulnerabilities and exposureUpdated Microsoft Defender documentation in defender-endpoint/migrating-asr-rules.md.
- Security Operations Guide for Teams protection
Office 365 · Email and collaborationUpdated Microsoft Defender documentation in defender-office-365/mdo-support-teams-sec-ops-guide.md.
- Microsoft Defender XDR: Email summary powered by Security Copilot on the email entity page
Defender XDR · GeneralMicrosoft Defender XDR will add an AI-powered Email summary via Security Copilot on the Email entity page, launching in public preview mid-April 2026 and generally available by mid-May 2026. It provides concise threat insights, timeline analysis, URL and attachment assessments, requiring Security Copilot access and SCUs.
- Attack Surface Reduction Rules ReferenceEndpoint · Vulnerabilities and exposure
Updated Microsoft Defender documentation in defender-endpoint/attack-surface-reduction-rules-reference.md.
- How Microsoft names threat actors
Unified SecOps · GeneralUpdated Microsoft Defender documentation in unified-secops-platform/microsoft-threat-actor-naming.md.
This period briefing was assembled from the tracked Microsoft Learn and Message Center changes.
18 updates
Microsoft Defender XDR
3 updatesUpdated Microsoft Defender documentation in defender-xdr/experts-on-demand.md.
UrlClickEvents
UpdatedUpdated Microsoft Defender documentation in defender-xdr/advanced-hunting-urlclickevents-table.md.
Microsoft Defender for Endpoint
4 updates
Updated Microsoft Defender documentation in defender-endpoint/whats-new-in-microsoft-defender-endpoint.md.
Updated Microsoft Defender documentation in defender-endpoint/microsoft-defender-endpoint-releases.md.
Updated Microsoft Defender documentation in defender-endpoint/migrating-asr-rules.md.
Updated Microsoft Defender documentation in defender-endpoint/attack-surface-reduction-rules-reference.md.
Microsoft Defender for Office 365
10 updatesUpdated Microsoft Defender documentation in defender-office-365/mdo-support-teams-sec-ops-guide.md.
Updated Microsoft Defender documentation in defender-office-365/submissions-teams.md.
Submissions Teams
UpdatedUpdated Microsoft Defender documentation in defender-office-365/submissions-teams.md.
Updated Microsoft Defender documentation in defender-office-365/mdo-support-teams-quick-configure.md.
Updated Microsoft Defender documentation in defender-office-365/defender-for-office-365-whats-new.md.
Updated Microsoft Defender documentation in defender-office-365/mdo-support-teams-sec-ops-guide.md.
Updated Microsoft Defender documentation in defender-office-365/mdo-support-teams-sec-ops-guide.md.
Mdo Support Teams About
UpdatedUpdated Microsoft Defender documentation in defender-office-365/mdo-support-teams-about.md.
Updated Microsoft Defender documentation in defender-office-365/defender-for-office-365-whats-new.md.
Teams Message Entity Panel
UpdatedUpdated Microsoft Defender documentation in defender-office-365/teams-message-entity-panel.md.
Updated Microsoft Defender documentation in unified-secops-platform/microsoft-threat-actor-naming.md.