Microsoft Windows Defender Antivirus STIG: WNDF-AV-000040

Check: WNDF-AV-000040 (in versions v2 r2 through v1 r4)

Title

Windows Defender AV must be configured for automatic remediation action to be taken for threat alert level High. (Cat II impact)

Discussion

This policy setting allows you to customize which automatic remediation action will be taken for each threat alert level. Threat alert levels should be added under the Options for this setting. Each entry must be listed as a name value pair. The name defines a threat alert level. The value contains the action ID for the remediation action that should be taken. Valid threat alert levels are: 1 = Low 2 = Medium 4 = High 5 = Severe Valid remediation action values are: 2 = Quarantine 3 = Remove 6 = Ignore

Check Content

Verify the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows Defender Antivirus -> Threats -> "Specify threat alert levels at which default action should not be taken when detected" is set to "Enabled". Click the “Show…” box option and verify the ‘Value name’ field contains a value of “4” and the ‘Value’ field contains a “2". A value of “3” in the ‘Value’ field is more restrictive and also an acceptable value. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows Defender\Threats\ThreatSeverityDefaultAction Criteria: If the value "4" is REG_SZ = 2 (or 3), this is not a finding.

Fix Text

Set the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows Defender Antivirus -> Threats -> "Specify threat alert levels at which default action should not be taken when detected" to "Enabled". Select the “Show…” option box and enter "4” in the ‘Value name’ field and enter “2" in the ‘Value’ field.

Expert Comments

Expert comments are only available to logged-in users.

CCIs

CCIs tied to check.
Number Definition
CCI-001662

The information system takes organization-defined corrective action when organization-defined unacceptable mobile code is identified.

Controls

Controls tied to check. These are derived from the CCIs shown above.
Number Title
SC-18 (1)

Identify Unacceptable Code / Take Corrective Actions