MAL-2026-5087 Malicious code in buffer-utilities (npm)

buffer-utilities impersonates the legitimate buffer package by Feross Aboukhadijeh, copying its name, email, homepage, and GitHub repo metadata, and advertises itself as 'Node.js Buffer API, for the browser'. At require() time, index.js (lines 43-52) executes an IIFE that base64-decodes the string aHR0cHM6Ly93d3cuanNvbmtlZXBlci5jb20vYi9DV09WOQ== to https://www.jsonkeeper.com/b/CWOV9, performs an HTTP fetch, and passes the response's data.content field directly to eval(). jsonkeeper.com is a mutable anonymous JSON paste host: whoever controls the paste can change the executed payload at any time, with no version bump or republication of the package. Any application that imports buffer-utilities — including by accidental name confusion against the popular buffer package — runs whatever JavaScript the paste currently returns, with full process privileges. The base64-encoded URL constant is a deliberate obfuscation to defeat static URL scanning.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

The OpenSSF Package Analysis project identified 'buffer-utilities' @ 1.0.0 (npm) as malicious.

It is considered malicious because:

• The package communicates with a domain associated with malicious activity.

• The package executes one or more commands associated with malicious behavior.