{"id":"MAL-2026-18857","summary":"Malicious code in @kurtucoben/cstm-bail (npm)","details":"@kurtucoben/cstm-bail 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) 120363401967885236@newsletter (stored as base64 strings), using the victim's authenticated session and without telling them. Same behaviour as the PhantomSub family (MAL-2026-17342).","modified":"2026-11-09T23:15:23.548717155Z","published":"2026-10-27T00:00:00Z","database_specific":{"iocs":{"ips":[],"urls":[],"domains":[],"files":[{"digests":{"sha256":"17932079301cab87114fdd7fd33b3a0a0a46d591fe929b26334b5b815d44964e"},"paths":["lib/Socket/newsletter.js"]}]}},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/@kurtucoben/cstm-bail"},{"type":"WEB","url":"https://www.ox.security/blog/phantomsub-malicious-npm-campaign-secretly-adds-users-to-whatsapp-spam-channels/"}],"affected":[{"package":{"name":"@kurtucoben/cstm-bail","ecosystem":"npm","purl":"pkg:npm/%40kurtucoben/cstm-bail"},"versions":["1.0.0"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/@kurtucoben/cstm-bail/MAL-2026-18857.json"}}],"schema_version":"1.9.2","credits":[{"name":"CyberXYZ","contact":["https://cyberxyz.io"],"type":"FINDER"}]}