fulfillment-cuprum-auth-widgetnpm
Advisory published Updated
fulfillment-cuprum-auth-widget is a confirmed malicious npm package (MAL-2026-16176) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 3.7.0-rc-37, 3.7.1…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in fulfillment-cuprum-auth-widget (npm)
What this malware does
The package's preinstall script (index.js) runs automatically on npm install and collects host identifiers via os.hostname(), os.userInfo(), os.homedir(), and DNS lookups, then JSON-stringifies the entire process.env and POSTs both payloads to a hardcoded external host at https://l2ha5tswnm71286wnjgrngvb4tyejmdpe.i.dr0gas.com/exf. Bulk process.env serialization on developer and CI machines captures whatever secrets are present in the environment (cloud credentials, registry tokens, CI secrets). The destination domain is unrelated to any legitimate npm publisher and follows a dependency-confusion exfiltration pattern (long random subdomain under an attacker-controlled apex).
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for fulfillment-cuprum-auth-widget (4 malicious versions).
If you installed it — respond
fulfillment-cuprum-auth-widget is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If fulfillment-cuprum-auth-widget was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks fulfillment-cuprum-auth-widget-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.