Malicious Code Injection in yonzofficial: A Covert Channel Subscription Vulnerability
Summary
MAL-2026-17414: Malicious code in yonzofficial (npm). Affects yonzofficial versions 2.1.0 – 2.1.3. No fix is published. How to fix ↓
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Background
The 'yonzofficial' package is part of a larger family of npm packages that are forks of the Baileys WhatsApp Web library. These packages are designed to facilitate interactions with the WhatsApp platform. However, they have been identified to contain malicious code that compromises user accounts by subscribing them to unwanted channels without consent.
Vulnerability Detail
The vulnerability arises from the injection of malicious code into the WhatsApp socket layer, which executes an unauthorized FOLLOW query using the installer's authenticated session. This allows attackers to silently subscribe victims to channels they did not choose, leveraging obfuscation techniques to hide the target JIDs from casual inspection. The malicious action does not exfiltrate credentials or execute arbitrary code but exploits the user's authenticated session for nefarious purposes.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall yonzofficialIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a temporary workaround, users can remove the 'yonzofficial' package from their project until a secure version is confirmed. This can be done with the command: npm uninstall yonzofficial.
Conclusion
The 'yonzofficial' package contains a serious vulnerability that allows malicious actors to exploit users' WhatsApp sessions to subscribe them to unwanted channels. It is crucial for users to update to the latest version or remove the package to mitigate this risk.
See every vulnerability recorded for yonzofficial →
FAQ
The 'yonzofficial' package is an npm package that interacts with the WhatsApp platform, but it has been identified to contain malicious code.
The vulnerability allows attackers to subscribe users to unwanted WhatsApp channels using their authenticated session without their consent.
Users may notice unexpected subscriptions to channels or newsletters they did not join, which could indicate exploitation of this vulnerability.
Yes, you can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time using just your package-lock.json file.
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