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

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.

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.

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".