Valid certificates, stolen accounts: how attackers broke npm's last trust signal

On May 19, 633 malicious npm package versions passed Sigstore provenance verification. They were cleared by the system because the attacker had generated valid signing certificates from a compromised maintainer account.Sigstore worked exactly as designed: it verified the package was built in a CI environment, confirmed a valid certificate was issued, and recorded everything in the transparency log. What it cannot do is determine whether the person holding the credentials authorized the publish — and that gap turned the last automated trust signal in npm into camouflage.One day earlier, StepSecurity documented an attack on the Nx Console VS Code extension, a widely used developer tool with more than 2.2 million lifetime installs. Version 18.95.0 was published using stolen credentials on May