yazxz

GHSA-jj9r-vwq8-cq7x

Malicious code in yazxz (npm)

Details

**Severity:** Critical

**Affected versions:** `= 3.0.0`

yazxz 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 sends the WhatsApp w:mex FOLLOW query for the channel ID(s) 120363403463420361@newsletter, 120363405622645148@newsletter, 120363406290651839@newsletter, 120363422741438435@newsletter, 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/yazxz/MAL-2026-19041.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/f8bd377e5c522af8e1a7cf92b0cd17dcdba7a45f/osv/malicious/npm/yazxz/MAL-2026-19041.json
- https://www.npmjs.com/package/yazxz
- https://www.ox.security/blog/phantomsub-malicious-npm-campaign-secretly-adds-users-to-whatsapp-spam-channels
- https://github.com/advisories/GHSA-jj9r-vwq8-cq7x

Compromised versions (1)

= 3.0.0

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