Risky Bulletin Newsletter
October 13, 2025
Risky Bulletin: Microsoft revamps Edge's "IE Mode" after zero-day attacks
Presented by
News Editor
A mysterious threat actor is abusing the legacy Internet Explorer mode in Microsoft Edge to run malicious code in a user's browser and take over their device.
The attacks have been going on since at least August, according to the Microsoft Edge security team.
The Internet Explorer legacy mode, or IE Mode, is a separate website execution environment in Edge. It works by reloading a web page but running its code inside the old Internet Explorer engines.