Malicious Code Execution Vulnerability in c2-client Package
Summary
MAL-2026-17165: Malicious code in c2-client (npm). Affects c2-client versions 1.0.0. No fix is published. How to fix ↓
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Background
The c2-client package is an npm module designed for command and control (C2) operations. It is intended for use in environments where automated control of systems is necessary. However, this package has been identified as containing malicious code that can execute unauthorized commands on the installer's machine during installation, posing significant security risks.
Vulnerability Detail
The vulnerability originates from a postinstall hook defined in the package.json file of the c2-client package. This hook executes a setup script (setup.js) automatically when the package is installed. The script runs with the privileges of the user installing the package and has access to the network, allowing it to potentially establish a command channel controlled by an attacker or execute arbitrary code. This behavior is classified under CWE-506, indicating the presence of embedded malicious code.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
npm uninstall c2-clientIf 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 installing the c2-client package altogether. If it is already installed, you can remove it using the command: npm uninstall c2-client. Additionally, consider using a tool like Vulert to monitor your project for vulnerabilities.
Conclusion
The c2-client package has been identified as containing malicious code that can execute unauthorized commands during installation. It is essential to remove this package from your project and monitor for any updates or patches. Utilizing tools like Vulert can help you stay informed about vulnerabilities in your dependencies.
See every vulnerability recorded for c2-client →
FAQ
The c2-client package is an npm module designed for command and control operations, allowing automated management of systems.
The vulnerability manifests through a postinstall hook that executes a setup script, which can run malicious code with the installer's privileges.
The risks include unauthorized code execution, potential data breaches, and the establishment of a command channel controlled by an attacker.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
If you have installed the c2-client package, you should uninstall it immediately using the command: npm uninstall c2-client.
