Malicious Code Detected in @coopeuch/button: A Critical Vulnerability
Summary
MAL-2026-17759: Malicious code in @coopeuch/button (npm). Affects @coopeuch/button versions 1.999.999. No fix is published. How to fix ↓
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Background
The @coopeuch/button package is an npm library that is intended for use in various JavaScript applications. It is designed to provide button functionalities within web applications. However, a severe vulnerability has been identified in version 1.999.999, where malicious code is executed during the installation process, compromising user data and system integrity.
Vulnerability Detail
The vulnerability originates from the package's postinstall lifecycle script (postinstall.js), which automatically runs during the npm install process. This script collects sensitive information from the installer host, including hostname, username, UID/GID, home directory, network interfaces, and more. It then sends this data to a hardcoded external server (collector.oob.s4yhii.com) via HTTPS. This behavior not only poses a risk to the user's privacy but also indicates a potential dependency confusion attack, where the public package replaces an intended internal package.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall @coopeuch/buttonIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a temporary workaround, avoid using the @coopeuch/button package until a patched version is released. Additionally, consider using alternative packages that provide similar functionalities without the associated risks.
Conclusion
The @coopeuch/button package has a critical vulnerability that allows malicious code to harvest sensitive information during installation. It is essential to update the package to a safe version and monitor your dependencies to prevent future risks.
See every vulnerability recorded for @coopeuch/button →
FAQ
The vulnerability involves malicious code that collects sensitive information from the user's system during installation.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Visit Vulert Scanner to check your application without signing up.
If you have installed version 1.999.999, it is recommended to uninstall the package and update to a patched version as soon as it becomes available.
Regularly monitor your dependencies using tools like Vulert and keep your packages updated to minimize the risk of vulnerabilities.
The consequences include unauthorized data collection, potential data breaches, and compromised system integrity.
