MAL-2026-17341

This package is part of a large family (100+ identified as of September 2026) of near-identical forks of the Baileys WhatsApp Web library that inject a covert channel-subscription action into the WhatsApp socket layer. On connect, the injected code issues an authenticated w:mex FOLLOW query (query_id 7871414976211147) against one or more attacker-chosen WhatsApp Channel/Newsletter JIDs, using the installer's own authenticated WhatsApp session -- silently subscribing the victim's account to channels it never asked to join.

The target JID(s) are hidden from casual source review via one of several obfuscation techniques observed across the family: a plain string literal, base64 encoding, base64+XOR, or a char-code array reconstructed at runtime. Some variants instead fetch a mutable, attacker-controlled remote JSON/JS list of target JIDs from GitHub or another host at runtime, letting the target list change after installation without a new npm publish. Every sample in the family shares the same underlying mechanism (a wrapped/patched socket-connect routine that fires the FOLLOW query some seconds after connect), even though the package name, JID value(s), and obfuscation/delivery method differ per fork.

The malicious action abuses the installer's own authenticated WhatsApp session to gain reach and subscribers for attacker-controlled channels; it does not exfiltrate credentials, establish persistence, or execute arbitrary remote code.

Affected package: @badzz88/baileys (npm), version(s): 8.5.9, 8.5.7, 8.5.5, 8.5.4, 8.5.3, 8.5.2, 8.5.1.

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Source: amazon-inspector (8c4fc02c3ef351d891d52e60719cbd702d2f6a1db2d00847ac02ae7928de67b9)

package.json declares a required runtime dependency whatsapp-rust-bridge-baron resolved to github:7ucg/whatsapp-rust-bridge with no commit SHA, tag, or integrity hash. On npm install, npm fetches the current default-branch HEAD of that repository and installs it into node_modules. The GitHub account 7ucg is not the publisher of this npm package (published under Badzz88), so an unrelated third party controls the code that lands on the installer's machine. The bridge module is required throughout the crypto, decode, and Noise-handler paths, so its code executes as soon as a consumer imports the package. Because the source is a mutable branch owned by a non-publisher account, the fetched bytes can change silently between installs, and there is no verification that today's HEAD matches any previously reviewed content. This is the classic unpinned-mutable-source install-time code-execution channel. Additional network/child_process/os primitives referenced in src/Utils/generics.js and src/Utils/messages-media.js are consistent with the upstream Baileys library shape (media download, ping-based connectivity checks) and are not by themselves evidence of exfiltration in this fork.