A major and ongoing supply-chain attack is currently targeting developers through the OpenVSX and Microsoft Visual Studio Code (VS Code) extension marketplaces via a self-spreading malware dubbed "GlassWorm" that has triggered an estimated 35,800 installations to date.
The campaign leverages novel techniques, such as embedding malicious code within invisible Unicode characters, enabling it to bypass detection and make the threats literally invisible in code editors. GlassWorm not only infects extensions, but also uses compromised accounts to further propagate itself, posing an accelerating risk through the dependency and update mechanisms of these platforms.
The malware focuses on stealing credentials for GitHub, npm, and OpenVSX accounts, as well as harvesting cryptocurrency wallet information from 49 different extensions. It then escalates the compromise by deploying a SOCKS proxy on infected machines, facilitating covert malicious traffic, and by installing HVNC (Hidden Virtual Network Computing) clients for undetectable remote access.
GlassWorm leverages a hardcoded Solana blockchain wallet that participates in transactions used to distribute base64-encoded links pointing to its next-stage payload, referred to by researchers as the obfuscated "ZOMBI" module. Once installed, ZOMBI transforms the workstation into a node of a decentralized criminal infrastructure, enabling persistent and stealthy cybercriminal operations.
Unique for its resilience, GlassWorm's operators use the Solana blockchain as the primary command-and-control channel, making takedown efforts extremely challenging due to the blockchain’s decentralized, persistent, and anonymous nature. Secondary methods for controlling infected hosts include embedding payload links in Google Calendar event titles and directly contacting specific IP addresses (e.g., 217.69.3[.]218). To ensure redundancy and robust communication, the malware also incorporates BitTorrent’s Distributed Hash Table (DHT).
Researchers at Koi Security have identified at least eleven infected extensions on OpenVSX, with some still available for download as of reporting, and one on Microsoft’s VS Code Marketplace. Notably, the auto-update feature in VS Code means users can become infected without any interaction—the malicious version of extensions is silently pushed to all endpoints. Microsoft quickly removed the compromised extension following the alert, while some extension publishers have issued security updates.
These attacks follow a wider trend, echoing last month’s Shai-Hulud worm attack that affected 187 npm packages. Koi Security warns that the sophistication, propagation methods, and resilience of GlassWorm represent a significant escalation in the threat landscape, underscoring the urgent need for enhanced supply-chain security and vigilant monitoring.
