AI Sidebar Spoofing Attack: SquareX Uncovers Malicious Extensions that Impersonate AI Browser Sidebars

SquareX released critical research exposing a new class of attack targeting AI browsers. The AI Sidebar Spoofing attack leverages malicious browser extensions to impersonate trusted AI sidebar interfaces, which is used to trick users into executing dangerous commands that can lead to credential theft, device hijacking, and password exfiltration.

The research demonstrates how attackers can exploit users’ trust in AI browser sidebars – the primary interface through which users interact with AI browsers like Comet, as well as consumer browsers with AI features like Brave and Edge. By creating pixel-perfect replicas of legitimate AI sidebars, malicious extensions return AI-generated responses that include harmful instructions that unsuspecting users follow.

“AI has become an essential tool for millions of users to learn new skills and complete tasks. Unfortunately, this has created a dangerous dynamic where people blindly follow AI-generated instructions without the expertise to identify security risks,” explains Vivek Ramachandran, Founder and CEO ...