The Download signed ActiveX controls property must be disallowed (Restricted Sites zone).

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-223051	SRG-APP-000209	DTBI112-IE11	SV-223051r879629_rule	2023-12-01	2

Description
ActiveX controls can contain potentially malicious code and must only be allowed to be downloaded from trusted sites. Signed code is better than unsigned code in that it may be easier to determine its author, but it is still potentially harmful, especially when coming from an untrusted zone.

ℹ️ Check
The policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Internet Control Panel -> Security Page -> Restricted Sites Zone -> 'Download signed ActiveX controls' must be 'Enabled', and 'Disable' selected from the drop-down box. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4 Criteria: If the value "1001" is REG_DWORD = 3, this is not a finding.

ℹ️ Check

The policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Internet Control Panel -> Security Page -> Restricted Sites Zone -> 'Download signed ActiveX controls' must be 'Enabled', and 'Disable' selected from the drop-down box. Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4 Criteria: If the value "1001" is REG_DWORD = 3, this is not a finding.

✔️ Fix
Set the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Internet Control Panel -> Security Page -> Restricted Sites Zone -> 'Download signed ActiveX controls' to 'Enabled', and select 'Disable' from the drop-down box.