Malware in clsx-js
Malware discovered in the npm package clsx-js. Systems with this package installed are considered fully compromised and require immediate remediation.
- Disclosed
- Last updated
- Blast radius
- Any system with clsx-js installed or running
- Ecosystems
- Attack vectors
- Affected entities
- clsx-jsnpm package
A malware-laden version of the npm package clsx-js has been identified and published to the npm registry. The package is flagged as critical severity by GitHub's advisory system.\n\nAccording to the advisory, any computer with this package installed or running should be considered fully compromised. The malware grants outside entities full control of affected systems.\n\nImmediate remediation requires rotating all secrets and keys from a different, uncompromised computer, and removing the package. However, due to the level of system compromise, removal of the package alone may not eliminate all malicious software installed as a result of the initial compromise.
Indicators of compromise
- Packages
- clsx-js
Remediation
- Immediately rotate all secrets, keys, and credentials from a different, uncompromised computer
- Remove the clsx-js package from all affected systems
- Conduct a full security audit and malware scan of all systems that had clsx-js installed
- Review system logs and network traffic for signs of unauthorized access or data exfiltration
- Consider full system reimaging if compromise is confirmed
Sources
- GitHub Advisory GHSA-8jmh-pvvx-wjrf · GitHub Advisory Database
Cite this entry
"Malware in clsx-js." supplychainattack.org, Supply Chain Attack Incident Catalog. Disclosed June 9, 2026; last updated June 9, 2026. https://supplychainattack.org/incident/malware-in-clsx-js-v29yur
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