Spoofed AI sidebars can trick Atlas, Comet users into dangerous actions

SquareX researchers demonstrated an "AI Sidebar Spoofing" attack against agentic AI browsers (Perplexity Comet and OpenAI Atlas) in which a malicious browser extension injects a realistic fake AI sidebar overlay that intercepts user interactions. The report outlines realistic scenarios — crypto-phishing, OAuth-based Gmail/Drive hijacking, and pushing reverse-shell installation commands — and advises avoiding sensitive tasks in these browsers until security matures.