Malicious AI Extensions in VSCode Marketplace Steal Developer Data, Impacting 1.5 Million Users
In January 2026, researchers at Koi Security discovered that two AI-powered Visual Studio Code (VSCode) Marketplace extensions—ChatGPT – 中文版 and ChatMoss (CodeMoss)—were secretly exfiltrating developer files and sensitive data to China-based servers. Together, these malicious extensions had been installed 1.5 million times and collected data using real-time file monitoring, workspace file harvesting, and covert user profiling via embedded commercial analytics SDKs. The compromised extensions transmitted not only source code but potentially included API keys, configuration, and credential files without user consent, representing a major supply-chain compromise in the software development ecosystem. This incident highlights the persistent risks developers face from supply chain attacks through third-party plugins. As AI-driven code assistants surge in popularity, attackers are increasingly exploiting trusted extension marketplaces to deploy sophisticated data-stealing campaigns, raising urgent concerns for software security, compliance, and marketplace governance.
Kill Chain