MAL-2026-4515 Malicious code in chai-val (npm)

Malicious package Published
Package
chai-val
Registry
npm

What is MAL-2026-4515?

MAL-2026-4515 is a malicious package in chai-val, published on 21 May 2026.

Official description

The package masquerades as a pino-logger helper (file structure, exports, and keywords are copied from pino) but its main entry exports a middleware that spawns node lib/caller.js as a detached child process. caller.js performs an HTTP GET to https://jsonkeeper.com/b/XRGF3 and passes the response's .cookie field directly into new Function.constructor('require', s), invoking it with the host's require — granting the fetched script full Node.js capabilities (filesystem, network, child_process, env). The destination URL is additionally stored base64-encoded as DEV_API_KEY: "aHR0cHM6Ly9qc29ua2VlcGVyLmNvbS9iL1hSR0Yz", an obfuscation of the same C2 endpoint. jsonkeeper.com is an anonymous, mutable paste host: today's content can be replaced by the operator at any moment without republishing the npm package. Any developer who installs chai-val and invokes the advertised middleware export triggers arbitrary remote code execution under their Node process.

What should I do about MAL-2026-4515?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

Sources

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