Microsoft Teams to protect against malicious URLs, dangerous file types

Microsoft recently revealed that it’s currently enhancing protection against dangerous file types and malicious URLs in Teams chats and channels.

“Microsoft Teams now blocks messages containing weaponizable file types, such as executables, in chats and channels, increasing protection against malware and other file-based attacks,” the company said in a Microsoft 365 roadmap update this week.

“Microsoft Teams can now detect and warn users on malicious URLs sent in Teams chat and channels, increasing protection against malware attacks,” it added in a separate entry.

Both of these features are currently in development and are expected to begin rolling out worldwide across standard Microsoft 365 multi-tenants next month.

On Monday, the company also announced in the Microsoft 365 Message Center that Teams now integrates with the Microsoft Defender for Office 365 Tenant Allow/Block List, enabling security administrators to block incoming communications (chats, channels, meetings, and calls) from blocked domains.

Security admins will also be able to automatically delete existing communications from users in blocked domains and manage blocked external domains in Microsoft Teams via the Microsoft Defender portal.

This feature is now in a targeted release phase and will reach general availability worldwide by late September 2025.

Earlier this year, Microsoft introduced another Teams feature that started rolling out in July 2025, preventing users from capturing screenshots of sensitive information shared during meetings.

“To address the issue of unauthorized screen captures during meetings, the Prevent Screen Capture feature ensures that if a user attempts to take a screen capture, the meeting window will turn black, thereby protecting sensitive information,” it said.

In January, the company also reminded Microsoft 365 admins that its new Teams Chat brand impersonation protection feature, designed to alert users of phishing attacks targeting organizations with external Teams access enabled, will be available to all customers by mid-February 2025.

At last year’s Enterprise Connect conference, Redmond announced that Teams had reached over 320 million monthly active users across 181 markets and 44 languages.