Microsoft Defender for Office 365 - Safe Links

You might see this dialog if your company admin has configured Safe Links scanning in your Office 365 or Microsoft 365 applications, and link scanning is taking longer to process. You can select Skip Verification to cancel the scan, but we recommend waiting until the scan is complete for protection against potential malicious links.

Part of Microsoft Defender for Office 365, Safe Links scans URLs for malicious content during mail flow and again at time of click. Safe Links scanning helps protect you and your organization from malicious links that are used in phishing and other attacks.

Why scan URLs at time of click? Attackers have become more sophisticated in how they try to breach organizations. Instead of sending malicious links directly to end users, attackers now send benign links in messages. After the messages have been delivered, the attackers reconfigure and redirect the benign links to malicious sites. Even though many end users are trained to identify and report malicious links in messages, link redirection makes scanning the URL again at time of click a critical layer of protection to act on behalf of end users.