Malicious Code Injection in @bellaxchuu/skyblue: Covert Channel Subscription Vulnerability
Summary
MAL-2026-17347: Malicious code in @bellaxchuu/skyblue (npm). Affects @bellaxchuu/skyblue versions 2.1.2. No fix is published. How to fix ↓
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Background
The @bellaxchuu/skyblue package is a fork of the Baileys WhatsApp Web library, designed to facilitate interactions with WhatsApp's web interface. It is part of a larger family of similar packages that have been identified as potentially malicious. This package allows users to connect to WhatsApp, but it has been compromised to include malicious code that can exploit the user's authenticated session.
Vulnerability Detail
The vulnerability arises from the injection of malicious code that executes upon establishing a connection to WhatsApp. This code sends an unauthorized FOLLOW query to attacker-controlled WhatsApp channels using the victim's authenticated session. The malicious action is obfuscated to hide the target JIDs from casual review, employing techniques like string literals, base64 encoding, and dynamic fetching of target lists. This allows attackers to silently subscribe victims to channels without their consent, although it does not exfiltrate credentials or execute arbitrary code.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall @bellaxchuu/skyblueIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a temporary measure, you can remove the @bellaxchuu/skyblue package from your project to prevent exploitation. Use the following command: npm uninstall @bellaxchuu/skyblue. Additionally, consider using alternative libraries that do not have known vulnerabilities.
Conclusion
The @bellaxchuu/skyblue package contains a significant vulnerability that allows for unauthorized channel subscriptions using the victim's WhatsApp session. Users are advised to update or remove the package to protect themselves from potential exploitation. Utilizing tools like Vulert can help monitor for such vulnerabilities in real-time.
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FAQ
The vulnerability involves malicious code that subscribes users to WhatsApp channels without their consent, using their authenticated session.
You can check if your application is affected by using Vulert, which monitors vulnerabilities in your package-lock.json file. Visit Vulert Scanner for a quick assessment.
If you are using this package, it is crucial to update to the latest version or remove it entirely to mitigate the risk of exploitation.
No, the vulnerability does not exfiltrate user credentials but abuses the authenticated session to subscribe to channels.
Yes, consider using other reputable libraries for WhatsApp Web integration that do not have known vulnerabilities.
