Microsoft Teams will let admins block custom file extensions
Microsoft Teams will soon let administrators tweak the list of file extensions commonly associated with malware and security threats to meet their company's security requirements.
This will come as an update to Weaponizable File Protection, a built-in Teams messaging safety feature that scans conversations and blocks chat or channel messages with dangerous, high-risk file attachments.
As detailed in a new Microsoft 365 roadmap entry, the feature is currently in development and will start rolling out in November 2026.
"Microsoft Teams is expanding admin controls for Weaponizable File Protection. Administrators will be able to customize which file types are blocked in Teams to align with their organization's security requirements or continue using the Microsoft-recommended default list," Microsoft says.
"This added flexibility helps organizations tailor file protection policies while maintaining a secure collaboration environment."
When it reaches general availability, it will be available across Android, desktop, iOS, macOS, and web platforms for standard multi-tenant cloud environments worldwide.
Right now, according to Microsoft's support website, admins can't change the list of blocked file types.
More Teams security improvements
Starting in December, admins can also block external users via the Defender portal to thwart cybercrime gangs(including ransomware groups) attempting to abuse Teams in social engineering attacks targeting victims' employees.
Earlier this month, it said that Teams will get a new security feature designed to provide additional protection against phishing and fraud attempts by blurring QR codes sent by external senders.
This week, Microsoft also announced that, starting in November, it will let users report suspicious guest invitations directly from Teams to help their organization's security teams identify and block phishing attempts and other attacks through guest invitations.
More recently, Microsoft has begun rolling out a new Teams meeting protection policy that lets admins automatically block all identified external bots from joining meetings.
References in this story
- Foaie de parcurs pentru inteligența artificială la lucru | Microsoft 365 www.microsoft.com Foaia de parcurs Microsoft 365 listează actualizările planificate în prezent pentru abonații eligibili. Căutați aici mai multe informații despre starea noilor caracteristici și actualizări.
- Weaponizable file protection in Microsoft Teams - Microsoft Teams learn.microsoft.com Learn about weaponizable file protection in Microsoft Teams.
- Microsoft Teams to let admins block external users via Defender portal www.bleepingcomputer.com Microsoft announced that security administrators will soon be able to block external users from sending messages, calls, or meeting invitations to members of their organization via Teams.
- Microsoft Teams voice calls abused to push Matanbuchus malware www.bleepingcomputer.com The Matanbuchus malware loader has been seen being distributed through social engineering over Microsoft Teams calls impersonating IT helpdesk.
- Black Basta ransomware poses as IT support on Microsoft Teams to breach networks www.bleepingcomputer.com The BlackBasta ransomware operation has moved its social engineering attacks to Microsoft Teams, posing as corporate help desks contacting employees to assist them with an ongoing spam attack.
- Foaie de parcurs pentru inteligența artificială la lucru | Microsoft 365 www.microsoft.com Foaia de parcurs Microsoft 365 listează actualizările planificate în prezent pentru abonații eligibili. Căutați aici mai multe informații despre starea noilor caracteristici și actualizări.
- Foaie de parcurs pentru inteligența artificială la lucru | Microsoft 365 www.microsoft.com Foaia de parcurs Microsoft 365 listează actualizările planificate în prezent pentru abonații eligibili. Căutați aici mai multe informații despre starea noilor caracteristici și actualizări.
- Microsoft Teams now lets admins block external bots from meetings www.bleepingcomputer.com Microsoft is rolling out a new Teams meeting protection policy that allows administrators to automatically block all identified external bots from joining Teams meetings.
