Mark of the Web Windows Zero-Day Receives Unofficial Patch

MotW is an essential security mechanism, especially when it comes to malicious Microsoft Office documents that contain macros. By default, Office will only block macros in files that contain the MotW, allowing threat actors to abuse this flaw to smuggle in malicious macros with no warning to users. It is recommended to disable macros via Group Policy until Microsoft releases an official patch for the MotW flaw.

https://www.bleepingcomputer.com/news/microsoft/windows-mark-of-the-web-bypass-zero-day-gets-unofficial-patch/