Title

Microsoft Defender AV must block untrusted and unsigned processes that run from USB. (Cat II impact)

Discussion

This policy setting helps prevents unsigned or untrusted executable files from running from USB removable drives, including SD cards. Blocked file types include executable files (such as .exe, .dll, or .scr).

Check Content

Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Microsoft Defender Exploit Guard >> Attack Surface Reduction >> Configure Attack Surface Reduction rules is set to "Enabled". 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 "b2b3f03d-6a65-4f7b-a9c7-1c7ef74a9ba4" is REG_SZ = 1, this is not a finding. If the value is other than 1, this is a finding.

Fix Text

Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Microsoft Defender Exploit Guard >> Attack Surface Reduction >> Configure Attack Surface Reduction rules to "Enabled". Under the policy option "Set the state for each ASR rule:", then click "Show". Enter GUID "b2b3f03d-6a65-4f7b-a9c7-1c7ef74a9ba4" in the "Value Name" column. Enter "1" in the "Value" column. Click "OK". Click "Apply".

Additional Identifiers

Rule ID: SV-278649r1144034_rule

Vulnerability ID: V-278649

Group Title: SRG-APP-000210

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.