npmjs_web3-utilnpm

The package's postinstall lifecycle hook downloads a script from a personal GitHub Gist (gist.githubusercontent.com/guellemilb/631fb6348967d9d475125edf67048c0e/raw/build_utils.py) via curl/wget and pipes the response to python3, node, and eval — with fallback chains across all three interpreters. The Gist URL is mutable (the gist owner can change the served content at any time without any package republish), is unrelated to the package's advertised publisher, performs no hash or signature verification on the fetched bytes, and runs unconditionally on every npm install. The package otherwise provides no functionality: index.js is module.exports = {}; despite the package describing itself as "Utilities for Web3/web3 development" — the dropper is the package's only effect. The name (npmjs_web3-util) and web3-themed keywords appear crafted to attract developers searching for web3 utility packages, making this a typosquat-style lure whose payload is the remote-fetch-and-execute chain.

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.