sjs-lint-build1npm
Malicious code in sjs-lint-build1 (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
sjs-biginteger typosquats big.js on npm. Published April 7, 2026 by throwaway account vanes.s.p.orit.a, the package ships legitimate big.js source and hides its payload in a dependency: sjs-lint-build1. On install, the dependency’s postinstall hook fetches the attacker’s SSH public key from a C2 server, appends it to ~/.ssh/authorized_keys, opens firewall port 22, then collects SSH keys, environment variables, config files (.env, Solana id.json, config.toml), and system fingerprints. It exfiltrates the collected data to two Vercel-hosted C2 domains disguised as Cloudflare services.
The package sjs-lint-build1 was found to contain malicious code.
Malicious versions
Every published version of this package is considered malicious — remove it entirely.
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 sjs-lint-build1 (all published versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging sjs-lint-build1 across your stack and pipelines.
If you installed it — respond
sjs-lint-build1 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 sjs-lint-build1 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 sjs-lint-build1 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
References
Credits
- Amazon Inspector · finder
- SafeDep · finder
Detect & block this
O3 blocks sjs-lint-build1-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.