Security researchers reported multiple risks tied to AI-themed browser extensions in the Chrome/Edge ecosystem, including active malicious campaigns. Malwarebytes identified 16 malicious extensions (15 Chrome, 1 Edge) masquerading as ChatGPT “enhancers” that steal ChatGPT session tokens, enabling attackers to take over accounts and access conversation history and metadata; the extensions also exfiltrate additional telemetry (e.g., extension version/language and usage details) to help attackers profile victims and maintain longer-term access.
Separately, Varonis described a new malware-as-a-service offering called “Stanley” that claims to reliably get phishing-capable Chrome extensions through Chrome Web Store review, using full-screen iframe overlays to present attacker-controlled login pages while the address bar continues to show the legitimate domain; it also advertises auto-install support across Chrome/Edge/Brave, a management panel, geo/IP targeting, and frequent C2 polling. In parallel with these overtly malicious cases, an Incogni study of 442 AI-powered Chrome extensions found broad privacy and security exposure from over-privileged extensions (e.g., script injection and deep page access) and extensive data collection (52% collecting user data), highlighting that even popular tools (e.g., Grammarly and QuillBot) can present significant privacy risk due to the scope of permissions and data categories collected.

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The researchers behind the ChatGPT-themed extension findings notified Google and Microsoft about the malicious add-ons in their stores. Users were advised to uninstall the listed extensions because store review processes had failed to prevent the abuse.
Researchers identified 16 malicious browser extensions, including 15 for Chrome and 1 for Edge, that posed as ChatGPT productivity tools. The extensions stole ChatGPT session authentication tokens, allowing attackers to hijack accounts and access users' conversation history and related metadata.
In its 2026 report, Incogni ranked Grammarly and QuillBot among the most potentially privacy-damaging widely used AI browser extensions because of broad access and multiple categories of collected data. The researchers noted these extensions were not rated as highly likely to be malicious, but still posed notable privacy concerns.
Incogni released a report analyzing 442 AI-powered Chrome extensions and found that many request extensive permissions and collect significant user data. The study said 52% of reviewed extensions collected some form of user data, including potentially sensitive information such as personal communications, location, and website content.
BleepingComputer contacted Google for comment regarding claims that Stanley operators can get phishing extensions approved in the Chrome Web Store. The outreach followed publication of Varonis' findings about the service's capabilities and distribution model.
Varonis researchers reported a malware-as-a-service offering called "Stanley" that allegedly sells malicious Chrome extensions designed to pass Chrome Web Store review. The extensions use full-screen iframe overlays to phish users while keeping the browser address bar on a legitimate domain.
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