Time-of-click protection for URLs
Microsoft now provides «time-of-click» checking of the URLs found in email messages and documents such as MS Word files and spread-sheets.
The ability to check URLs is now built into Outlook, Outlook-Web-Access and the various MS Office applications. This feature is available for Microsoft 365 users, where the mailboxes and files are stored in the cloud.
Each time that you click on a URL, a Microsoft filtering server checks the reputation of that URL and, if necessary, opens the URL in a «sandbox» environment to be sure that the URL is safe. This may slow down your work a bit, but it is necessary to provide protection against URLs that have been changed to point to a malware-downloader AFTER you have received the email or document. This is a delayed use of the URL as a threat: first the URL was safe, later it was no longer safe because it is now potentially harmful.
See also Enhanced threat detection with URL click alerts by Microsoft Defender for Office 365
