# Malicious Ad-blocker Extensions Exfiltrate AI Chat Data

> Source: <https://letsdatascience.com/news/malicious-ad-blocker-extensions-exfiltrate-ai-chat-data-8ab72a28>
> Published: 2026-06-30 10:49:00+00:00

Editorial analysis: For practitioners, browser-side extensions with broad page access create a straightforward vector for sensitive prompt and response leakage, changing threat models for prompt engineering and data governance. Notebookcheck reports that security researchers at MalExt Sentry uncovered a campaign they call "PromptSnatcher" on June 13, 2026, in which two extensions posing as ad blockers - "Smart Adblocker" (extension ID iojpcjjdfhlcbgjnpngcmaojmlokmeii, about **80,000** users) and "Adblock for Browser" (ID jcbjcocinigpbgfpnhlpagidbmlngnnn, about **10,000** users) - quietly recorded conversations from roughly **90,000** users. Notebookcheck writes that the extensions captured chats from eight AI platforms, including `ChatGPT`, `Gemini`, and `Claude`, storing up to **10,000** characters of prompts and **30,000** characters of responses and sending the data to developer servers via an internal engine the researchers call `Panel 231`.