Malicious Chrome Extension Steal ChatGPT and DeepSeek Conversations from 900K Users

Malicious Chrome Extension Steal ChatGPT and DeepSeek Conversations from 900K Users

Two rogue Chrome extensions have compromised over 900,000 users by secretly exfiltrating ChatGPT and DeepSeek conversations, along with full browsing histories, to attacker servers.

Discovered by OX Security researchers, the malware impersonates the legitimate AITOPIA AI sidebar tool, with one fake even earning Google’s “Featured” badge.

The OX Research team identified the threat during routine analysis, revealing extensions that clone AITOPIA’s interface for chatting with LLMs like GPT and Claude.

Malicious Chrome Extension Steal ChatGPT and DeepSeek Conversations from 900K Users

Named “Chat GPT for Chrome with GPT-5, Claude Sonnet & DeepSeek AI” (600K+ users, ID: fnmihdojmnkclgjpcoonokmkhjpjechg, version 1.9.6) and “AI Sidebar with Deepseek, ChatGPT, Claude and more” (300K+ users, ID: inhcgfpbfdjbjogdfjbclgolkmhnooop), they request “anonymous analytics” consent to mask data theft.

Malicious Chrome Extension Steal ChatGPT and DeepSeek Conversations from 900K Users

Threat actors host privacy policies on Lovable.dev to obscure origins, and uninstalled extensions redirect to the other.

How the Malware Operates

Installed extensions monitor tabs via chrome.tabs.onUpdated API, generating a unique “gptChatId” per victim. On detecting chatgpt.com or deepseek.com URLs, they scrape DOM elements for prompts, responses, and session IDs, storing data locally before Base64-encoding and sending batches to C2 servers like deepaichats.com or chatsaigpt.com every 30 minutes.

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Malicious Chrome Extension Steal ChatGPT and DeepSeek Conversations from 900K Users
Malicious Chrome Extension Steal ChatGPT and DeepSeek Conversations from 900K Users 7

This captures proprietary code, business strategies, PII, search queries, and internal URLs missed by AITOPIA’s disclosed server storage.​

Stolen chats risk exposing intellectual property, corporate secrets, and personal data for espionage or sale on dark web forums. Browsing logs reveals habits, tokens, and org structures, enabling phishing or identity theft across affected enterprises.

As of January 7, 2026, both extensions remain downloadable, with the first stripped of its “Featured” status post-disclosure but updated as recently as October 2025.​

Users should visit chrome://extensions, remove by ID, or use store pages: ChatGPT extension, AI Sidebar. Avoid unverified extensions regardless of badges; stick to reputable sources.

IoCs

Type Value Notes
Extension name Chat GPT for Chrome with GPT-5, Claude Sonnet & DeepSeek AI Malicious AI sidebar-style extension
Extension ID fnmihdojmnkclgjpcoonokmkhjpjechg Chrome Web Store ID
Version 1.9.6 Reported malicious build
SHA-256 hash 98d1f151872c27d0abae3887f7d6cb6e4ce29e99ad827cb077e1232bc4a69c00 Package hash
Extension name AI Sidebar with Deepseek, ChatGPT, Claude and more Second malicious extension
Extension ID inhcgfpbfdjbjogdfjbclgolkmhnooop Chrome Web Store ID
Version 1.6.1 Reported malicious build
SHA-256 hash 20ba72e91d7685926c8c1c5b4646616fa9d769e32c1bc4e9f15dddaf3429cea7 Package hash

Network and C2 IoCs

Category Domain / Endpoint Notes
C2 endpoint deepaichats[.]com Receives stolen chat data and URLs
C2 endpoint chatsaigpt[.]com Additional C2 for exfiltrated data
Lovable-hosted server chataigpt[.]pro Used for privacy policy / infra hosting
Lovable-hosted server chatgptsidebar[.]pro Used for uninstall redirect and infra

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