Malicious code in virtualcpu (PyPI)

virtualcpu Updated 02 Oct 2025

Summary

24/02/2023
CRITICAL
No i
Critical
Not published

MAL-2023-7817: Malicious code in virtualcpu (PyPI). Affected versions are not published. No fix is published. How to fix ↓

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Background

The virtualcpu package is an open-source Python package available on PyPI. It is designed to provide a virtual CPU implementation for various purposes. The package allows users to simulate CPU operations and execute code within a virtual environment. However, the package has been found to contain malicious code, which poses a significant security risk to users.

Vulnerability Detail

The virtualcpu package has been compromised by the EsqueleSquad group, who published nearly 6000 malicious PyPi and NPM packages. These packages execute spyware and information-stealing malware. The specific vulnerability in virtualcpu allows the execution of unauthorized code, leading to potential data breaches, unauthorized access, and other malicious activities. The malicious code can be triggered when using the affected package, putting users' systems and data at risk.

How To Fix

This package is malicious. Remove it and rotate any credentials it could have accessed.

pip uninstall virtualcpu

If it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.

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Workaround

There is no known workaround for this vulnerability. It is essential to remove the affected package and follow the recommended steps to fix the issue.

Conclusion

The virtualcpu package on PyPI has been compromised by the EsqueleSquad group, leading to the distribution of malicious code. This vulnerability poses a significant risk to users, potentially resulting in data breaches and unauthorized access. It is crucial to remove the affected package and follow the recommended steps to mitigate the impact. For further support and guidance on vulnerability remediation, contact DevNack.com.

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FAQ

You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability. Simply provide your Pipfile.lock file, and Vulert will analyze it in real-time and alert you if any open-source vulnerabilities, including this one, are detected.

The malicious code in the virtualcpu package can lead to various consequences, including data breaches, unauthorized access to sensitive information, and the installation of additional malware or spyware on affected systems. It is crucial to take immediate action to mitigate the risks associated with this vulnerability.

At the time of this report, there is no specific evidence of exploitation in the wild related to this vulnerability. However, given the widespread distribution of the malicious packages by the EsqueleSquad group, it is essential to treat this vulnerability seriously and take appropriate measures to protect your systems.

While the presence of malicious packages on PyPI and NPM is concerning, it is important to note that the majority of packages available on these repositories are safe and well-maintained. However, it is crucial to exercise caution and follow best practices when selecting and using packages. Regularly updating packages and monitoring for security advisories can help mitigate the risks associated with using open-source dependencies.

If you come across any suspicious packages or vulnerabilities, it is recommended to report them to the respective package repository or the maintainers of the affected package. Additionally, you can reach out to the Vulert team at info@devnack.com for further support and guidance on vulnerability remediation.

How To Fix

This package is malicious. Remove it and rotate any credentials it could have accessed.

pip uninstall virtualcpu

If 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 →

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