Researchers at OX Security have identified 101 malicious npm packages belonging to the PhantomSub campaign. The packages target developers who install what appear to be modified versions of the open-source Baileys library for WhatsApp automation.
Instead of building legitimate bots, the packages silently subscribe connected WhatsApp accounts to promotional channels. The hidden logic activates only after an authenticated session is established, meaning a single download is insufficient to trigger the behavior.
Among the detected package names are ourin-baileys, neuralwhatsapp, and @nexustechpro/baileys. The campaign operators store target channel lists in three ways: by fetching them from GitHub, embedding them in plaintext within the code, or using encoded identifiers. The GitHub method allows operators to update targets without releasing new package versions.
Collectively the packages have been downloaded approximately 490,000 times, with 116,000 downloads recorded in the last 30 days. These figures represent downloads rather than confirmed victims. As of 28 September, npm had removed only 16 of the malicious packages.
The inflated subscriber counts help channels that sell bots, game resources, accounts, and promotion services appear more popular. Disabled notifications further conceal the unwanted subscriptions from victims. Multiple packages share identical channel lists, indicating that several independent libraries funnel audiences to the same recipients.
OX Security recommends auditing project dependencies, reviewing WhatsApp subscriptions, blocking suspicious channels, and avoiding the use of personal accounts with untrusted packages.
