Malicious Code Injection in @user-services/web-components: Telemetry Probe Vulnerability
Summary
MAL-2026-16379: Malicious code in @user-services/web-components (npm). Affects @user-services/web-components versions 9.9.10. No fix is published. How to fix ↓
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Background
The @user-services/web-components package is an npm library designed for web component development within user services. It provides reusable components that can be integrated into various applications. However, version 9.9.10 of this package has been found to contain malicious code that compromises user data security.
Vulnerability Detail
The vulnerability originates from a hidden telemetry probe embedded in the @user-services/web-components package. This probe activates during the npm install lifecycle and on every require() of the module. It collects sensitive information such as the username, hostname, and current working directory, which it sends to an attacker-controlled server. The malicious code is obfuscated to evade detection by static analysis tools, making it particularly dangerous as it can exfiltrate user identity data without consent.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall @user-services/web-componentsIf 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 @user-services/web-components package from your project until a patched version is available. Use the following command to uninstall the package: npm uninstall @user-services/web-components.
Conclusion
The @user-services/web-components package version 9.9.10 contains a serious vulnerability due to embedded malicious code that exfiltrates user data. It is crucial to update to a patched version or remove the package to protect against potential data breaches.
See every vulnerability recorded for @user-services/web-components →
FAQ
The malicious code is a telemetry probe that collects sensitive user information and sends it to an external server.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. By analyzing your package-lock.json file, Vulert can help you identify if your application is affected.
If an immediate update is not possible, consider removing the package from your project as a temporary measure to mitigate risk.
Yes, you can use the Vulert playground at Vulert Scanner to check for vulnerabilities in your application without requiring any signup.
The consequences include unauthorized access to sensitive user information, which could lead to identity theft or other malicious activities.
