Windows Defender AV must be configured block Office applications from creating executable content.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-77969	WNDF-AV-000034	SV-92665r1_rule		Medium

Description
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.

STIG	Date
MS Windows Defender Antivirus Security Technical Implementation Guide	2018-03-29

Details

Check Text ( C-77579r1_chk )
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 -> Windows Defender Antivirus -> Windows 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.

Check Text ( C-77579r1_chk )

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 -> Windows Defender Antivirus -> Windows 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 (F-84681r1_fix)
Set the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows 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”.