checkout-public-tokensnpm
checkout-public-tokens is a confirmed malicious npm package (MAL-2026-12589) that steals credentials and exfiltrates sensitive data (malicious version 35.4.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in checkout-public-tokens (npm)
What this malware does
On require() of checkout-public-tokens, index.js loads platform.js which downloads an opaque binary payload from hardcoded string-split-obfuscated hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev), with a DNS-TXT base64 fallback resolver via sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The payload is written to /tmp or %TEMP% under a disguised name (.cache<hex> or dotnet_diag_<hex>.exe), chmodded to 0755, and spawned detached via /bin/sh -c or cmd.exe /c start /b. Destination hostnames are constructed at runtime by joining split literals, and in-file comments frame the download-and-execute chain as telemetry, analytics, and cache validation. The package advertises itself as a token utility; the hosts and behavior are unrelated to any documented purpose and there is no hash or signature verification of the fetched bytes.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for checkout-public-tokens (version 35.4.9). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging checkout-public-tokens across your stack and pipelines.
If you installed it — respond
checkout-public-tokens 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 checkout-public-tokens was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks checkout-public-tokens before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks checkout-public-tokens-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.