Title

Microsoft Defender AV must be configured block Office applications from creating executable content. (Cat II impact)

Discussion

This rule targets typical behaviors used by suspicious and malicious add-ons and scripts (extensions) that create or launch executable files. This is a typical malware technique. Extensions will be blocked from being used by Office apps. Typically these extensions use the Windows Scripting Host (.wsh files) to run scripts that automate certain tasks or provide user-created add-on features.

Check Content

This setting is applicable starting with v1709 of Windows 10. It is NA for prior versions. Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Microsoft Defender Exploit Guard >> Attack Surface Reduction >> "Configure Attack Surface Reduction rules" is set to "Enabled”. Click "Show...". Verify the rule ID in the Value name column and the desired state in the Value column is set as follows: Value name: 3B576869-A4EC-4529-8536-B80A7769E899 Value: 1 Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules Criteria: If the value "3B576869-A4EC-4529-8536-B80A7769E899" is REG_SZ = 1, this is not a finding.

Fix Text

Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Windows Defender Exploit Guard >> Attack Surface Reduction >> "Configure Attack Surface Reduction rules" to "Enabled". Click "Show...". Set the Value name to "3B576869-A4EC-4529-8536-B80A7769E899" and the Value to "1".

Additional Identifiers

Rule ID: SV-213458r823085_rule

Vulnerability ID: V-213458

Group Title: SRG-APP-000210

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.