yukistage

MAL-2026-19042

Malicious code in yukistage (npm)

Details

yukistage 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) 120363400911374213@newsletter, using the victim's authenticated session and without telling them. Same behaviour as the PhantomSub family (MAL-2026-17342).

Compromised versions (1)

1.1.7

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