Malicious Code Injection in running_leopon_z3n Package
Summary
MAL-2025-96423: Malicious code in running_leopon_z3n (npm). Affected versions are not published. No fix is published. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
The running_leopon_z3n package is part of the npm ecosystem, which is widely used for JavaScript package management. This package has been identified as part of a malicious campaign that aims to exploit npm's publishing system. It is designed to automatically generate and publish derivative packages with randomized names, which can lead to reputation inflation for developers involved in the tea.xyz token reward campaign. The vulnerability stems from the package's ability to modify its own package.json file, posing a significant risk to developers and users alike.
Vulnerability Detail
The vulnerability in the running_leopon_z3n package originates from its malicious code that modifies the package.json file to remove private flags and change version numbers. This allows the package to continuously republish itself and its variants, polluting the npm registry with potentially harmful packages. The malicious payload can lead to unauthorized access, data corruption, and a compromised development environment, making it critical for users to address this issue promptly.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall running_leopon_z3nIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
Tip — Not sure whether your app is affected? Vulert can check the versions your app actually runs. Scan free →
Workaround
As a temporary workaround, you can prevent the execution of the malicious code by removing the running_leopon_z3n package from your dependencies. Use the following command to uninstall it: npm uninstall running_leopon_z3n.
Conclusion
The running_leopon_z3n package poses a significant risk due to its malicious code that modifies package.json files and republish variants. It is crucial for developers to take immediate action by updating or removing the package to safeguard their projects from potential harm.
See every vulnerability recorded for running_leopon_z3n →
FAQ
It is an npm package that has been identified as part of a malicious campaign to exploit the npm registry.
The vulnerability can lead to unauthorized modifications of your package.json file and the potential for malicious code to be executed in your development environment.
You should immediately uninstall the package and check for any unauthorized changes in your project.
Yes, you can use tools like Vulert, which monitors your package-lock.json file for open-source vulnerabilities in real-time.
Yes, you can use the Vulert playground at Vulert Scanner to check for vulnerabilities in your application without any signup.
