The lilys-baileys npm package versions 1.3.2 and 1.3.3 contain malicious code that hooks into the WhatsApp socket connection process. Upon connection, it issues an authenticated 'w:mex' FOLLOW query to subscribe the victim's WhatsApp account to attacker-chosen channels or newsletters. The target channel JIDs are obfuscated using methods such as base64 encoding, XOR, or runtime reconstruction, and some variants retrieve the target list dynamically from attacker-controlled remote sources. This covert subscription mechanism abuses the victim's authenticated session to increase subscribers for attacker channels without exfiltrating credentials or executing arbitrary remote code.

Victims unknowingly subscribe their WhatsApp accounts to attacker-controlled channels, potentially exposing them to unwanted content or spam. The attack does not compromise account credentials, establish persistence, or allow arbitrary code execution, limiting its impact to unauthorized channel subscriptions.

No official patch or remediation guidance is provided. Users should avoid installing or using the lilys-baileys package versions 1.3.2 and 1.3.3. Since this is a malicious package distributed via npm, verifying package authenticity and using trusted sources is recommended. Patch status is not yet confirmed — check the vendor advisory or npm security advisories for current remediation guidance.