STIGQter: STIG Summary: Microsoft Defender Antivirus Security Technical Implementation Guide Version: 2 Release: 9 Benchmark Date: 01 Jul 2026:

Microsoft Defender AV must convert warn verdict to block.

DISA Rule

SV-278677r1192829_rule

Vulnerability Number

V-278677

Group Title

SRG-APP-000210

Rule Version

WNDF-AV-000074

Severity

CAT II

CCI(s)

• CCI-001170 - Prevents the automatic execution of mobile code in organization-defined software applications.

Weight

10

Fix Recommendation

Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Network Inspection System >> Convert warn verdict to block to "Enabled".

Check Contents

Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Network Inspection System >> Convert warn verdict to block is set to "Enabled"; otherwise, this is a finding.

Procedure: Use the Windows Registry Editor to navigate to the following key:
HKLM\Software\Policies\Microsoft\Windows Defender\NIS

Criteria: If the value "EnableConvertWarnToBlock" is REG_DWORD = 1, this is not a finding.

If the value is 0, this is a finding.

Vulnerability Number

V-278677

Documentable

False

Rule Version

WNDF-AV-000074

Severity Override Guidance

Verify the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Defender Antivirus >> Network Inspection System >> Convert warn verdict to block is set to "Enabled"; otherwise, this is a finding.

Procedure: Use the Windows Registry Editor to navigate to the following key:
HKLM\Software\Policies\Microsoft\Windows Defender\NIS

Criteria: If the value "EnableConvertWarnToBlock" is REG_DWORD = 1, this is not a finding.

If the value is 0, this is a finding.

Check Content Reference

M

Target Key

3985