Malicious Chrome extensions disguised as AI assistants steal data from 300,000+ users

Malicious Chrome Extensions Target Users Through AI Assistant Disguise

A widespread cybersecurity threat has emerged as more than 30 malicious Chrome extensions disguised as AI chatbots have been installed by at least 300,000 users, according to research from LayerX Security 1

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. The AiFrame campaign, as researchers have named it, represents a sophisticated attempt to steal credentials and emails by exploiting the growing popularity of AI assistants 5

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. These extensions impersonate well-known services including ChatGPT, Claude, Gemini, and Grok, while others present themselves as generic AI tools promising to summarize documents, write messages, and provide Gmail assistance 1

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What makes this threat particularly concerning is that many of these extensions remain available on the Chrome Web Store at the time of reporting, with some even earning the "Featured" badge 1

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. The most popular extension, AI Sidebar, currently shows 70,000 users, while AI Assistant has 60,000 users, and ChatGPT Translate has 30,000 users . Google has not responded to inquiries about the malicious extensions as of publication 1

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How the AiFrame Campaign Operates to Steal Sensitive User Data

All 32 extensions in the AiFrame campaign share identical underlying codebases, permissions, and backend infrastructure, communicating with servers under the tapnetic[.]pro domain 1

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. Rather than implementing AI functionality locally, these extensions deliver promised features by rendering a full-screen iframe that loads content from a remote domain 2

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. This iframe overlay visually appears as the extension's interface but enables operators to remotely update their malicious functionalities at any time without requiring Chrome Web Store approval 1

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When instructed by the iframe, extensions query the active tab and invoke a content script that extracts readable article content using Mozilla's Readability library 1

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. The extracted data includes titles, text content, excerpts, and site metadata from every website users visit, including sensitive authentication pages 3

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. This information, along with authentication details, is transmitted back to remote servers controlled by the extension operators 1

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. The extensions also support speech recognition through the Web Speech API, transcribing users' words and sending them to remote pages for operators to read 1

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Gmail Targeting and Man-in-the-Middle Attacks Raise Concerns

Nearly half of the extensions—15 in total—specifically target Gmail and share the same Gmail integration codebase 1

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. These extensions run a dedicated content script at 'document_start' on mail.google.com, allowing them to read visible email content directly from the DOM 2

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. The script repeatedly extracts message text via textContent from Gmail's conversation view, capturing email thread content and even draft or compose-related text 1

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. When Gmail-related features such as AI-assisted replies or summaries are invoked, the extracted email content is transmitted to third-party backend infrastructure outside Gmail's security boundary 2

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"The campaign exploits the conversational nature of AI interactions, which has conditioned users to share detailed information," explained LayerX Security researcher Natalie Zargarov. "By injecting iframes that mimic trusted AI interfaces, they've created a nearly invisible man-in-the-middle attack that intercepts everything from API keys to personal data before it ever reaches the legitimate service" 1

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. This approach represents a significant evolution in browser security threats, leveraging user trust in AI assistants to execute data exfiltration at scale 5

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Immediate Action Required for Affected Users

Users who have installed any of these extensions should delete them immediately by accessing Chrome's Extensions menu and checking against LayerX's complete list of indicators of compromise 2

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. After removal, affected individuals should reset passwords for all accounts, as the extensions may have captured authentication credentials across multiple services 2

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. The persistence of these extensions on the Chrome Web Store, despite affecting over 300,000 users, highlights ongoing challenges in browser security and the need for more robust vetting processes 3

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. Security experts recommend installing only official AI applications from trusted developers and using antivirus software to protect against such sophisticated scams 3

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. The incident serves as a reminder that while users have become more cautious with smartphone apps, browser extensions often receive less scrutiny despite having similarly broad access to sensitive information 4

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