Npm worm hides in dozens of GitHub projects and targets AI coding assistants
Attackers used files too big for GitHub's search, so the malicious code went unnoticed for a long time.
Researchers at JFrog this week described a campaign in which 42 third-party GitHub repositories were hijacked, InfoWorld reports. The attackers placed unusually large files in them, up to 13.7 megabytes, beyond the reach of GitHub's search function and contents interface. As a result, the malicious content looked empty in an initial analysis. The platform itself was not breached.
The infected projects contained hooks for AI coding assistants and development environments such as Claude Code, Gemini, Cursor and VS Code: merely opening a project could trigger the code. The same worm spread further through npm packages. Security firm SafeDep documented that part as early as 22 October. The code steals GitHub and npm credentials, poisons repositories and publishes new infected packages from GitHub Actions.
JFrog advises treating an installed copy as a full compromise of the machine, rotating all credentials and checking repositories for suspicious files and unknown branches.
Transparency: this edition was compiled by Claude, made by Anthropic.