Provides an overview of unsafe file types in Microsoft products. Lists Microsoft products that include safeguards to help protect customers from unsafe file types.

For a list of the unsafe file name extensions, see this Office support page. The following list describes how Outlook behaves when you receive or send an unsafe file attachment:

Using a compression utility, such as WinZip, creates a compressed archive file that has a different file name extension. Outlook doesn't recognize these file name extensions as potential threats.

Attachment Manager is a built-in security feature in Microsoft Windows that helps protect your device from potentially unsafe files. It works by identifying files downloaded from the internet or received via email that may pose a security risk.

The developer mode extension notification in Microsoft Edge helps protect you from security and privacy risks when using browser extensions. This feature alerts you about unverified or potentially unsafe extensions, helping keep you safe from malicious or bad actors.

There are a few different ways to do it, depending on your situation. In most cases you can unblock an XLL by modifying the properties of the file as follows: Open Windows File Explorer and go to the folder where you saved the file. Right-click the file and choose Properties from the context menu.

This change is designed to enhance security by preventing a vulnerability that could leak NTLM hashes when users preview potentially unsafe files. For more details, review the following frequently asked questions about this change.

To find the full list of blocked attachment types, follow the link below. Note: If you're using a Microsoft Exchange account, your email server administrator can unblock certain file types. Contact your administrator for more assistance. Blocked attachments in Outlook. Was this information helpful?

To protect your browser preferences, security, and privacy, Microsoft Edge automatically disables extensions that attempt to modify your default settings without permission. This article explains how Microsoft Edge manages extension behavior and how you can turn on an extension that has been disabled.

Learn how to manage extension permissions, control which websites extensions can access, and limit extension access to specific sites or all sites. This article also covers how to change, review and manage extension site permissions to improve browser security, privacy, and performance in Microsoft Edge.