Microsoft Defender AV must scan excluded files and directories during quick scans.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-278676	SRG-APP-000278	WNDF-AV-000072	SV-278676r1144075_rule	2025-11-25	2

Description
In Microsoft Defender Antivirus, when an exclusion for a file or folder is created, it will generally be skipped during both real-time protection and on-demand scans (including quick scans and full scans). However, with newer releases, the option exists to configure quick scans to include files and directories that are otherwise excluded from real-time protection.

ℹ️ Check
Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Scan >> Scan excluded files and directories during quick scans is set to "Enabled"; otherwise, this is a finding. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows Defender\Scan Criteria: If the value "QuickScanIncludeExclusions" is REG_DWORD = 1, this is not a finding. If the value is 0, this is a finding.

ℹ️ Check

Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Scan >> Scan excluded files and directories during quick scans is set to "Enabled"; otherwise, this is a finding. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows Defender\Scan Criteria: If the value "QuickScanIncludeExclusions" is REG_DWORD = 1, this is not a finding. If the value is 0, this is a finding.

✔️ Fix
Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Scan >> Scan excluded files and directories during quick scans to "Enabled". Click "OK". Click "Apply".