OpenSSF/OSV advisory MAL-2026-5835 confirms this npm version as malicious. On `npm install`, the package's `postinstall` hook runs `sec_check.js`, which enumerates the host's network interfaces and proceeds only if an IPv4 address begins with `18.175.` — a subnet-based targeting gate that hides the behavior on most developer/CI machines. When the gate passes, the script reads `<INIT_CWD>/myfile.txt` from the installer's working directory and uses `curl -X POST` to upload its contents to a...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in lab-helper (npm)
Details
On `npm install`, the package's `postinstall` hook runs `sec_check.js`, which enumerates the host's network interfaces and proceeds only if an IPv4 address begins with `18.175.` — a subnet-based targeting gate that hides the behavior on most developer/CI machines. When the gate passes, the script reads `<INIT_CWD>/myfile.txt` from the installer's working directory and uses `curl -X POST` to upload its contents to a hardcoded plaintext C2 at `http://18.175.63.47:8080/collect`. The combination of a lifecycle-script auto-execute path, network-identity targeting to evade scanners, hardcoded bare-IP exfiltration endpoint, and reading installer-side files matches a targeted supply-chain attack against a specific environment (likely an AWS/lab subnet).
## Source: ghsa-malware (0c9cd86dc5e0a1f19dccb8ecd8517d78b22afc17007d0d72a05ea18911395578) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Decision reason
OpenSSF Malicious Packages via OSV confirms lab-helper@0.0.2 as malicious (MAL-2026-5835): Malicious code in lab-helper (npm)