OpenSSF/OSV advisory MAL-2026-4572 confirms this npm version as malicious. Package name typosquats the popular `get-package-type` and reuses its README/exports verbatim, but adds `"postinstall": "node utils.cjs"` in package.json. utils.cjs is a 263 KB obfuscator.io-protected blob (string-array rotation with anti-debug `debugger` loops, RegExp toString fingerprint, and `Function('return this')` sandbox checks) that on `npm install`: (1) decodes a hardcoded base64+XOR-obfuscated URL and...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in get-package-lint (npm)
Details
Package name typosquats the popular `get-package-type` and reuses its README/exports verbatim, but adds `"postinstall": "node utils.cjs"` in package.json. utils.cjs is a 263 KB obfuscator.io-protected blob (string-array rotation with anti-debug `debugger` loops, RegExp toString fingerprint, and `Function('return this')` sandbox checks) that on `npm install`: (1) decodes a hardcoded base64+XOR-obfuscated URL and bearer token (HF_TOKEN), (2) HTTPS-GETs a platform-specific binary (linux-x64 / darwin-arm64 / win32-x64 selected via DOWNLOAD_MAP), (3) writes it under the user's local data directory, `chmod 0755` on POSIX, and spawns it detached, (4) installs OS-level persistence: on Windows via `reg add HKCU\...\CurrentVersion\Run`, on macOS via a LaunchAgent plist under `~/Library/LaunchAgents`, on Linux via a systemd user unit at `~/.config/systemd/user/<unit>.service` followed by `systemctl --user daemon-reload && enable && start`. The script also self-detaches by re-spawning itself with a `child` argv via `{detached:true, stdio:'ignore'}` and calling `process.exit(0)` so npm sees success while the dropper continues asynchronously. The fetched bytes are opaque, unverified (no hash/signature), and the source domain is not the package's publisher. This is an unambiguous binary-runner-dropper plus backdoor persistence triggered on every install.
Decision reason
OpenSSF Malicious Packages via OSV confirms get-package-lint@0.1.0 as malicious (MAL-2026-4572): Malicious code in get-package-lint (npm)