ultramaxo-baileys

GHSA-xm6h-mfw8-2pv8

Malicious code in ultramaxo-baileys (npm)

Details

**Severity:** Critical

**Affected versions:** `= 1.0.0`

ultramaxo-baileys is a fork of the Baileys WhatsApp Web library that silently subscribes the installer's own WhatsApp account to WhatsApp Channels chosen by the publisher. When the socket connects, code in lib/Socket/newsletter.js, lib/Socket/socket.js sends the WhatsApp w:mex FOLLOW query for the channel ID(s) 120363181827494553@newsletter, 120363402868866359@newsletter, 120363404790454890@newsletter, 120363405313529091@newsletter, 120363405441296892@newsletter, 120363405951960366@newsletter and 2 more (stored as character-code arrays), using the victim's authenticated session and without telling them. Same behaviour as the PhantomSub family (MAL-2026-17342).

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/f8bd377e5c522af8e1a7cf92b0cd17dcdba7a45f/osv/malicious/npm/ultramaxo-baileys/MAL-2026-19023.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/f8bd377e5c522af8e1a7cf92b0cd17dcdba7a45f/osv/malicious/npm/ultramaxo-baileys/MAL-2026-19023.json
- https://www.npmjs.com/package/ultramaxo-baileys
- https://www.ox.security/blog/phantomsub-malicious-npm-campaign-secretly-adds-users-to-whatsapp-spam-channels
- https://github.com/advisories/GHSA-xm6h-mfw8-2pv8

Compromised versions (1)

= 1.0.0

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.