Malicious Code Injection in horizontal_mouse_z3n Package
Summary
MAL-2025-103788: Malicious code in horizontal_mouse_z3n (npm). Affected versions are not published. No fix is published. How to fix ↓
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Background
The horizontal_mouse_z3n package is part of the npm ecosystem, typically utilized for various JavaScript functionalities. However, it has been identified as part of a malicious campaign that floods npm with derivative packages aimed at inflating developer reputation scores for token rewards. This package, like others in the campaign, contains scripts that automatically publish variants with altered metadata.
Vulnerability Detail
The vulnerability in the horizontal_mouse_z3n package stems from its malicious code that modifies the package.json file. This code removes private flags, alters version numbers, and generates random package names, leading to the continuous republishing of these variants. The origin of this vulnerability is linked to a broader campaign targeting npm, where packages are designed to pollute the registry and exploit developer reputation systems. The ramifications include potential security risks for applications relying on this package, as well as contributing to the degradation of the npm ecosystem.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall horizontal_mouse_z3nIf 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 horizontal_mouse_z3n package from your project by executing: npm uninstall horizontal_mouse_z3n. This will prevent any malicious code from executing until a secure version is available.
Conclusion
The horizontal_mouse_z3n package contains malicious code that poses significant risks to applications using it. It is crucial to update to a patched version or remove the package to maintain security. Utilizing tools like Vulert can help monitor and manage vulnerabilities effectively.
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FAQ
The horizontal_mouse_z3n package is an npm package that has been identified as part of a malicious campaign to inflate developer reputation scores.
The vulnerability can lead to unauthorized modifications in your package.json file, potentially compromising your application's integrity and security.
Yes, you can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time using just your package-lock.json file.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
If an immediate update is not possible, consider removing the package as a temporary measure to mitigate risks.
