Disable Trust Bar Notification for unsigned application add-ins and block them - notbpromptunsignedaddin - excel

Information

This policy setting controls whether the specified Office 2016 applications notify 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 an 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.

Solution

Policy Path: Microsoft Excel 2016\Excel Options\Security\Trust Center
Policy Setting Name: Disable Trust Bar Notification for unsigned application add-ins and block them

See Also

https://techcommunity.microsoft.com/t5/microsoft-security-baselines/security-baseline-for-microsoft-365-apps-for-enterprise-v2112/ba-p/3038172

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-18(4)

Plugin: Windows

Control ID: bcc94e9d3b6cf1c21a2fb9a51af8d5b84b2dc2aab027926addb5410e82c545e4