Malicious Chrome Extensions Steal ChatGPT and DeepSeek Conversations

Two rogue Chrome extensions, impersonating the legitimate AITOPIA AI sidebar tool, have compromised over 900,000 users by exfiltrating ChatGPT and DeepSeek conversations along with full browsing histories to attacker-controlled servers. The extensions, named "Chat GPT for Chrome with GPT-5, Claude Sonnet & DeepSeek AI" and "AI Sidebar with Deepseek, ChatGPT, Claude and more," request consent for "anonymous analytics" but covertly steal sensitive data, including proprietary code, business strategies, PII, and internal URLs. The malware operates by monitoring browser tabs, scraping chat content and session IDs, and sending Base64-encoded data to C2 servers every 30 minutes, exposing users to risks such as espionage, identity theft, and phishing.

Researchers from OX Security discovered the threat, noting that the extensions remain available on the Chrome Web Store, with one losing its "Featured" badge after disclosure. The extensions also redirect users to each other if uninstalled, and their privacy policies are hosted on third-party sites to obscure their origins. The incident highlights the growing trend of browser extensions being used to capture AI chatbot conversations, a tactic dubbed "Prompt Poaching," and underscores the need for vigilance when installing browser add-ons, especially those requesting broad permissions under the guise of analytics or enhanced user experience.