Microsoft is reworking how Microsoft 365 (previously Office 365) deals with Trusted Documents by making it more secure. Trusted Documents are essentially files that have active content like macros, ActiveX controls, data connections, and more. For Trusted Documents, there is no prompt when you open the file, even if new active content was added or you made changes in the existing active content. However, this is going to change soon.
According to the Microsoft 365 roadmap, Trusted Documents will not be able to override Protected View restrictions.
We are changing the behavior of Office applications to enforce policies that block Active Content (ex. macros, ActiveX, DDE) on Trusted Documents. Previously, Active Content was allowed to run in Trusted Documents even when an IT administrator had set a policy to block it. As part of ongoing Office security hardening, the IT administrator’s choice to block Active Content will now always take precedence over end-user set trusted documents.
Until now, Trusted Documents could override the Protected View restrictions that are imposed on other documents. Furthermore, even if an IT administrator had the policy to block active content, Trusted Documents used to follow the end users" precedence. Fortunately, Trusted Documents will now follow the IT admin policies.
Exploiting documents to attack computers is a very common technique to begin an attack. Recently, a malicious Microsoft Word document named "made on Windows 11 Alpha" was used as a maldoc that used VBA macros to drop a JavaScript payload upon successful exploitation. The macro was executed when the user clicked on "Enable editing" and "Enable content", which was instructed on the document"s cover.