Microsoft Windows Defender Antivirus STIG: WNDF-AV-000032

Check: WNDF-AV-000032 (in versions v2 r2 through v1 r2)

Title

Windows Defender AV must be configured to block executable content from email client and webmail. (Cat II impact)

Discussion

This rule blocks the following file types from being run or launched from an email seen in either Microsoft Outlook or webmail (such as Gmail.com or Outlook.com): Executable files (such as .exe, .dll, or .scr) Script files (such as a PowerShell .ps, VisualBasic .vbs, or JavaScript .js file) Script archive files

Check Content

This setting is applicable starting with v1709 of Windows 10, it is NA for prior versions. Verify the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows Defender Antivirus -> Windows Defender Exploit Guard -> Attack Surface Reduction -> "Configure Attack Surface Reduction rules" is set to "Enabled”. Click ‘Show...’. Verify the rule ID in the Value name column and the desired state in the Value column is set as follows: Value name: BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550 Value: 1 Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows Defender\Windows Defender Exploit Guard\ASR\Rules Criteria: If the value “BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550” is REG_SZ = 1, this is not a finding.

Fix Text

Set the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows Defender Antivirus -> Windows Defender Exploit Guard -> Attack Surface Reduction -> "Configure Attack Surface Reduction rules" to "Enabled”. Click ‘Show...’. Set the Value name to “BE9BA2D9-53EA-4CDC-84E5-9B1EEEE46550” and the Value to “1”.

Expert Comments

Expert comments are only available to logged-in users.

CCIs

CCIs tied to check.
Number Definition
CCI-001170

The information system prevents the automatic execution of mobile code in organization-defined software applications.

Controls

Controls tied to check. These are derived from the CCIs shown above.
Number Title
SC-18 (4)

Prevent Automatic Execution