Publisher must be configured to prompt the user when another application programmatically opens a macro.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-223390	SRG-APP-000207	O365-PU-000001	SV-223390r961086_rule	2025-03-05	3

Description
This policy setting controls whether the specified Office application notifies users when unsigned application add-ins are loaded or silently disable such add-ins without notification. This policy setting only applies if you enable the "Require that application add-ins are signed by Trusted Publisher" policy setting, which prevents users from changing this policy setting. If you enable this policy setting, applications automatically disable unsigned add-ins without informing users. If you disable this policy setting, if this application is configured to require that all add-ins be signed by a trusted publisher, any unsigned add-ins the application loads will be disabled and the application will display the Trust Bar at the top of the active window. The Trust Bar contains a message that informs users about the unsigned add-in. If you do not configure this policy setting, the disable behavior applies, and in addition, users can configure this requirement themselves in the "Add-ins" category of the Trust Center for the application.

Description

This policy setting controls whether the specified Office application notifies users when unsigned application add-ins are loaded or silently disable such add-ins without notification. This policy setting only applies if you enable the "Require that application add-ins are signed by Trusted Publisher" policy setting, which prevents users from changing this policy setting. If you enable this policy setting, applications automatically disable unsigned add-ins without informing users. If you disable this policy setting, if this application is configured to require that all add-ins be signed by a trusted publisher, any unsigned add-ins the application loads will be disabled and the application will display the Trust Bar at the top of the active window. The Trust Bar contains a message that informs users about the unsigned add-in. If you do not configure this policy setting, the disable behavior applies, and in addition, users can configure this requirement themselves in the "Add-ins" category of the Trust Center for the application.

ℹ️ Check
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Publisher 2016 >> Security >> Publisher Automation Security Level is set to "Enabled" "By UI (prompted)". Use the Windows Registry Editor to navigate to the following key: HKCU\software\policies\microsoft\office\common\security If the value automationsecuritypublisher is REG_DWORD = 2, this is not a finding.

✔️ Fix
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Publisher 2016 >> Security >> Publisher Automation Security Level to "Enabled" "By UI (prompted)"