MAL-2026-18121 Malicious code in my-auto-follow-eltio (npm)

npm package [email protected] is a fork of the Baileys WhatsApp library. Two of its source files, lib/Socket/chats.js (~140 KB) and lib/Socket/dugong.js (~96 KB), use a custom base85-style string-array plus per-function decoder scheme to obfuscate their contents. After decoding, the logic corresponds to ordinary Baileys chats-socket operations and WhatsApp message-format builders (payment, product, interactive, album, event, poll). The preinstall script only performs a Node.js version gate and the main entry is a library factory with no top-level side effects. No hardcoded attacker-controlled endpoints, remote code fetch, credential or home-directory reads, browser/wallet secret access, silent-relay of caller data, or lifecycle-time execution of external content are present. The package name suggests an 'auto-follow' behavior that could act with the connected WhatsApp account's identity, but no such covert action is observable in the visible code paths, and the obfuscation of a Baileys fork is an unusual authorship/transparency signal on its own.

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.