Malicious VSX Extension 'SleepyDuck' Uses Ethereum
🦆 Researchers at Secure Annex warned of a malicious Open VSX extension, juan-bianco.solidity-vlang, that delivers a remote access trojan dubbed SleepyDuck. Originally published as a benign library on October 31, 2025, it was updated to a malicious release after reaching about 14,000 downloads. The extension triggers on opening a code editor window or selecting a .sol file, harvesting host details and polling an Ethereum-based contract to obtain and update its command server. It also contains fallback logic using multiple Ethereum RPC providers to recover C2 information if the domain is taken down; users should only install extensions from trusted publishers and follow vendor guidance.
