MAL-2026-11139 Malicious code in kordyn (npm)

Malicious package Published
Package
kordyn
Registry
npm

What is MAL-2026-11139?

MAL-2026-11139 is a malicious package in kordyn, published on 28 Jul 2026.

Official description

[email protected] advertises itself in package.json and README as an unimplemented placeholder for trivial streak utilities ('Early release — placeholder. Implementation to come.'), but the tarball's declared main entry index.mjs is a 355 KB module whose bulk is a base64-encoded Windows PE executable. index.mjs imports writeFileSync, mkdirSync, readdirSync, and existsSync from 'fs' at the top level and reconstructs the embedded binary via Buffer.from(_cache, 'base64'), where _cache begins with 'TVqQAAMAAAAEAAAA//8AAL…' decoding to an MZ/PE header including the 'This program cannot be run in DOS mode' stub. Simply importing or requiring the package executes the decoding path, and the imported fs write APIs indicate the decoded PE is intended to be written to the installer's disk. The advertised functionality (streak-count helpers) has no legitimate reason to embed a native Windows executable, and the placeholder cover story is inconsistent with the shipped 355 KB opaque payload in the direction that conceals it from reviewers — the shape of a staged dropper / obfuscated loader.

What should I do about MAL-2026-11139?

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

Sources

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