Microsoft Defender Goes Crazy and Marks Safe Connections as Viruses

Microsoft confirmed that Defender made bugs (29) today and flagged legitimate links as malware, causing false alerts and a lot of problems for system administrators. The company announced the issue on Twitter, saying it was already aware of the incident.

System administrators discuss problems on social networks. One of those affected shared details about the error, stating that users may be receiving a very high volume of high severity alert emails.

We’re investigating an issue where legitimate URL links are incorrectly flagged as malicious by the Microsoft Defender service. Also, some of the alerts do not display the content as expected. More details can be found under DZ534539 in the admin center.

— Microsoft 365 Status (@MSFT365Status) 29 March 2023

The company explained that its engineers are investigating the service incident as a false positive and are reviewing service monitoring telemetry to develop a remediation plan. The error can be tracked in the Microsoft 365 Admin Center portal with code DZ534539.

Microsoft Defender Safe Connections Alert

Microsoft Defender has reported trusted links as malicious. (Source: Ctrl Blog/Playback)

Secure Connection Alert is a Microsoft Defender feature that provides an additional layer of protection against malicious links in emails, Teams messages, and Office apps. The purpose of the feature is to protect the organization against phishing and other types of cyber attacks that can compromise data security.

When turned on, the feature checks all links in email messages for suspicious activity. If the URL link is considered suspicious, Defender will display a warning to the user, alerting them to the potential risk.

If the user chooses to click the link, Defender monitors network traffic to ensure no malicious activity is taking place. With the flaw, users began to be bothered even when accessing trusted addresses.

But Secure Connection Alert is not a complete solution, it is an added layer of protection. To ensure security, it is necessary to implement a strategy with measures such as user awareness, firewalls and antivirus.