Title

Microsoft Defender AV must block persistence through WMI event subscription. (Cat II impact)

Discussion

This policy setting prevents malware from abusing WMI to attain persistence on a device. Fileless threats employ various tactics to stay hidden, to avoid being seen in the file system, and to gain periodic execution control. Some threats can abuse the WMI repository and event model to stay hidden.

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 "e6db77e5-3df2-4cf1-b95a-636979351e5b" is REG_SZ = 2, this is not a finding. If the value is other than 2, 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 "e6db77e5-3df2-4cf1-b95a-636979351e5b" in the "Value Name" column. Enter "2" in the "Value" column. Click "OK". Click "Apply".

Additional Identifiers

Rule ID: SV-278652r1144042_rule

Vulnerability ID: V-278652

Group Title: SRG-APP-000210

Expert Comments

CCIs tied to check.

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