The Microsoft Defender SmartScreen for Explorer must be enabled.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-253395	SRG-OS-000095-GPOS-00049	WN11-CC-000210	SV-253395r958478_rule	2025-02-25	2

Description
Microsoft Defender SmartScreen helps protect systems from programs downloaded from the internet that may be malicious. Enabling Microsoft Defender SmartScreen will warn or prevent users from running potentially malicious programs.

ℹ️ Check
This is applicable to unclassified systems, for other systems this is NA. If the following registry values do not exist or are not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\System\ Value Name: EnableSmartScreen Value Type: REG_DWORD Value: 0x00000001 (1) And Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\System\ Value Name: ShellSmartScreenLevel Value Type: REG_SZ Value: Block

ℹ️ Check

This is applicable to unclassified systems, for other systems this is NA. If the following registry values do not exist or are not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\System\ Value Name: EnableSmartScreen Value Type: REG_DWORD Value: 0x00000001 (1) And Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\Windows\System\ Value Name: ShellSmartScreenLevel Value Type: REG_SZ Value: Block

✔️ Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> File Explorer >> "Configure Windows Defender SmartScreen" to "Enabled" with "Warn and prevent bypass" selected. Windows 11 includes duplicate policies for this setting. It can also be configured under Computer Configuration >> Administrative Templates >> Windows Components >> Windows Defender SmartScreen >> Explorer.

✔️ Fix

Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> File Explorer >> "Configure Windows Defender SmartScreen" to "Enabled" with "Warn and prevent bypass" selected. Windows 11 includes duplicate policies for this setting. It can also be configured under Computer Configuration >> Administrative Templates >> Windows Components >> Windows Defender SmartScreen >> Explorer.