MAL-2026-15551 Malicious code in date-fns-sync (npm)
Malicious package
Published
MAL-2026-15551 is a malicious package: date-fns-sync (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-2026-15551/ (Markdown: https://insights.sbomify.com/MAL-2026-15551/index.md)
- Package
- date-fns-sync
- Registry
- npm
What is MAL-2026-15551?
MAL-2026-15551 is a malicious package in date-fns-sync, published on 29 Aug 2026.
Official description
package.json declares scripts.postinstall = 'node index.js'. index.js reconstructs a URL from a String.fromCharCode integer array — decoding to https://kongregate-api-config.vercel.app/ — fetches JSON from that endpoint, and passes the returned 'token' field directly to eval(). This executes attacker-controlled JavaScript on the installer's machine at npm install time. The destination is not a package publisher domain, the fetched payload is opaque and mutable, and the URL is deliberately concealed via char-code assembly to evade static analysis. The package's README describes it as a caching module, which does not match the observed behavior.
What should I do about MAL-2026-15551?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.