Microsoft Defender AV must be configured to block the Potentially Unwanted Application (PUA) feature.

Documentable No

Rule ID SV-213426r961197_rule

CCI References

CCI-001243

Discussion

After enabling this feature, PUA protection blocking takes effect on endpoint clients after the next signature update or computer restart. Signature updates take place daily under typical circumstances. PUA will be blocked and automatically quarantined.

Check Procedure

Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> "Configure detection for potentially unwanted applications" is set to "Enabled" and "Block".

Use the Windows Registry Editor to navigate to the following key: 

HKLM\Software\Policies\Microsoft\Windows Defender

If the value "PUAProtection" does not exist, this is a finding.

If the value "PUAProtection" is REG_DWORD = 1, this is not a finding.

Fix Action

Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> "Configure Detection for Potentially Unwanted Applications" to "Enabled" and "Block".