Malicious Code Injection in prastzyy Package: Unauthorized WhatsApp Channel Subscriptions
Summary
MAL-2026-17449: Malicious code in prastzyy (npm). Affects prastzyy versions 1.0.0. No fix is published. How to fix ↓
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Background
The prastzyy package is a fork of the Baileys WhatsApp Web library, designed to facilitate interactions with the WhatsApp Web API. It allows developers to build applications that can send and receive messages, manage contacts, and perform other WhatsApp-related tasks. However, this package has been identified as part of the 'PhantomSub' family, which has been compromised to include malicious functionalities that exploit users' authenticated WhatsApp sessions.
Vulnerability Detail
The vulnerability arises from the publisher's injection of code that covertly subscribes the user's WhatsApp account to various WhatsApp Channels without their consent. This is achieved by sending a FOLLOW query using the user's authenticated session. The injected code is located in the 'package/lib/Socket/newsletter.js' file, where it defines a list of channel identifiers and schedules follow requests for each channel upon establishing a connection. The lack of documentation and opt-out options exacerbates the issue, leading to unauthorized use of the victim's account to inflate the publisher's channel subscriber count.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall prastzyyIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a temporary workaround, you can remove the prastzyy package from your project by running the following command: npm uninstall prastzyy. This will prevent any malicious code from executing until a fix is available.
Conclusion
The prastzyy package has been compromised to include malicious code that exploits users' WhatsApp sessions for unauthorized channel subscriptions. Users are advised to update or uninstall the package to mitigate the risk. Utilizing tools like Vulert can help monitor for such vulnerabilities in real-time.
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FAQ
prastzyy is a fork of the Baileys WhatsApp Web library that allows developers to interact with the WhatsApp Web API.
The vulnerability allows the publisher to use your authenticated WhatsApp session to subscribe your account to channels without your consent.
No, the injected code does not provide any opt-out mechanism, making it impossible for users to prevent these subscriptions.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Visit Vulert Scanner to check your application without needing to sign up.
If you cannot update the package, it is recommended to uninstall it to prevent any potential exploitation.
