Microsoft Defender for Endpoints: Attack Surface Reduction (ASR)

Name: Microsoft Defender for Endpoints: Attack Surface Reduction (ASR)
Uploaded: 2026-10-27T00:00:00.000Z
Duration: 5 min 24 s
Description: Devices that report to Microsoft Defender for Endpoint still have plenty of doors attackers like to try, such as Office macros, downloaded scripts, and credential theft. This byte shows how attack surface reduction (ASR) rules close those doors, how Audit, Warn, and Block modes work, and how A.M Finances Group moved rules from Audit to Block without breaking the business.

Devices that report to Microsoft Defender for Endpoint still have plenty of doors attackers like to try, such as Office macros, downloaded scripts, and credential theft. This byte shows how attack surface reduction (ASR) rules close those doors, how Audit, Warn, and Block modes work, and how A.M Finances Group moved rules from Audit to Block without breaking the business.

What You Will Learn

What ASR rules protect against, and why they ask "should this app be doing that?" and not only "is this file malicious?"
Which three standard protection rules Microsoft recommends enabling directly in Block mode
How Audit, Warn, and Block modes work, and what each one does to your users
How to move rules from Audit to Block safely, using narrow exclusions

Microsoft Defender for Endpoints: Attack Surface Reduction (ASR)

What You Will Learn

Contributors