Microsoft Defender AV must be configured to not allow override of behavior monitoring.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-213440	SRG-APP-000210	WNDF-AV-000016	SV-213440r823052_rule	2022-04-08	2

Description
This policy setting configures a local override for the configuration of behavior monitoring. This setting can only be set by Group Policy. If this setting is enabled, the local preference setting will take priority over Group Policy. If this setting is disabled or not configured, Group Policy will take priority over the local preference setting.

ℹ️ Check
Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Real-time Protection >> "Configure local setting override for turn on behavior monitoring" is set to "Disabled" or "Not Configured". Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection Criteria: If the value "LocalSettingOverrideDisableBehaviorMonitoring" is REG_DWORD = 0, this is not a finding. If the value does not exist, this is not a finding. If the value is 1, this is a finding.

ℹ️ Check

Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Real-time Protection >> "Configure local setting override for turn on behavior monitoring" is set to "Disabled" or "Not Configured". Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection Criteria: If the value "LocalSettingOverrideDisableBehaviorMonitoring" is REG_DWORD = 0, this is not a finding. If the value does not exist, this is not a finding. If the value is 1, this is a finding.

✔️ Fix
Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Real-time Protection >> "Configure local setting override for turn on behavior monitoring" to "Disabled" or "Not Configured".