Vulnerability MAL-2026-18988

malvin-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 sends the WhatsApp w:mex FOLLOW query for the channel ID(s) 120363391079867105@newsletter, 120363399205146445@newsletter and a list downloaded at runtime from https://cdn.malvintech.sbs/file/chJids.json (the URL itself stored as base64 strings), using the victim's authenticated session and without telling them. Same behaviour as the PhantomSub family (MAL-2026-17342).