The 'nonexistent-package' in the npm ecosystem is identified as containing malicious code. Installation or execution of this package results in a full compromise of the affected computer, potentially allowing an attacker to control the system and access sensitive information. Due to the severity of the compromise, simply uninstalling the package may not remove all malicious artifacts or backdoors introduced. The advisory recommends treating any system with this package as fully compromised and taking immediate remediation steps such as secret rotation from a different machine.

Full system compromise on any computer with the package installed or running. All secrets and keys stored on the compromised system are at risk and should be rotated immediately. Removal of the package alone does not ensure complete remediation due to potential persistent malicious software.

Remove the 'nonexistent-package' from affected systems. Immediately rotate all secrets and keys stored on the compromised computer from a separate, secure device. Consider the system fully compromised and perform comprehensive incident response and remediation beyond package removal.