Prevent bypassing SmartScreen Filter warnings about files that are not commonly downloaded from the internet must be enabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-64713	DTBI1065-IE11	SV-79203r2_rule		Medium

Description
This policy setting determines whether the user can bypass warnings from SmartScreen Filter. SmartScreen Filter warns the user about executable files that Internet Explorer users do not commonly download from the internet. If you enable this policy setting, SmartScreen Filter warnings block the user. If you disable or do not configure this policy setting, the user can bypass SmartScreen Filter warnings.

Description

This policy setting determines whether the user can bypass warnings from SmartScreen Filter. SmartScreen Filter warns the user about executable files that Internet Explorer users do not commonly download from the internet. If you enable this policy setting, SmartScreen Filter warnings block the user. If you disable or do not configure this policy setting, the user can bypass SmartScreen Filter warnings.

STIG	Date
Microsoft Internet Explorer 11 Security Technical Implementation Guide	2019-09-23

Details

Check Text ( C-65455r4_chk )
If the system is on the SIPRNet, this requirement is NA. The policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Internet Explorer >> ”Prevent bypassing SmartScreen Filter warnings about files that are not commonly downloaded from the internet” must be ”Enabled”. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Internet Explorer\PhishingFilter. Criteria: If the value "PreventOverrideAppRepUnknown" is REG_DWORD = 1, this is not a finding.

Check Text ( C-65455r4_chk )

If the system is on the SIPRNet, this requirement is NA.

The policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Internet Explorer >> ”Prevent bypassing SmartScreen Filter warnings about files that are not commonly downloaded from the internet” must be ”Enabled”.

Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Internet Explorer\PhishingFilter.

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

Fix Text (F-70643r2_fix)
If the system is on the SIPRNet, this requirement is NA. Set the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Internet Explorer >> ”Prevent bypassing SmartScreen Filter warnings about files that are not commonly downloaded from the internet” to ”Enabled”.