Microsoft today announced the general availability of the Office 365 Safe Documents security feature. The feature uses Microsoft Defender Advanced Threat Protection to scan documents opened in Protected View and block users from editing them until a verdict is available. Microsoft: “People too often exit the protection sandbox without considering if the document is safe leaving their organizations vulnerable”” The feature is now available for all Office 365 ProPlus customers with Microsoft 365 E5 and E5 Security licenses for Commercial and Education customers on Windows clients on Windows.”
Source: https://www.bleepingcomputer.com/news/security/office-365-now-checks-docs-for-known-threats-before-editing/