MAL-2026-13480 Malicious code in @prototypevip/baileys (npm)

@prototypevip/baileys is a fork of the Baileys WhatsApp library. lib/Store/prototype-store.js registers a listener on the 'messages.upsert' event that runs on every incoming message. The listener body is obfuscated behind a base64 string table and a decoder (Buffer.from(s,'base64').toString('utf8')), which resolves to the property names 'type', 'md', 'ws', 'sendMessage', an Arabic message body ('you are no longer authorized to use this bot'), and the marker 'gintoki'. When the routine walks the message object and locates the active WhatsApp socket (type=='md', ws truthy), it compares an adjacent key against the decoded literal 'gintoki'. On any installer whose bot is not tagged with that hardcoded owner string, the code invokes the installer's own socket's sendMessage to broadcast the Arabic 'no longer authorized' notice through the installer's WhatsApp account and then throws 'Blocked' (also base64-decoded) to halt message handling. The behavior is undocumented, is hidden by base64 obfuscation of every relevant string, and abuses the installer's authenticated WhatsApp session as the delivery channel to send attacker-authored content to the installer's own contacts.