If this package is installed
Remove it, treat the machine (or CI runner) as compromised, and rotate every secret, token and key it could access — from a different, clean machine.
Details
Source: amazon-inspector (6fcfa5a90c6e60f1e3a94db0277e5d9bd0058d0d5d3a549e3e62dfb6e05f4223)
Package `eth-util` impersonates the legitimate `@ethereumjs/util` package: README, repository URL (github.com/ethereumjs/ethereumjs-monorepo), badges, contributor list, and module API are copied from the ethereumjs project, but the package is published under the unrelated short name `eth-util`. The compiled `dist/index.js` at line 55 contains a side-effect-only `require("assert-kit")` that is absent from `src/index.ts` and from the parallel `dist.browser/index.js` bundle — tsc would not emit an unreferenced require of a package not present in the source, so this line was injected post-compile. Anyone reading the GitHub source would not see the loader; only the published npm tarball carries it. The `assert-kit` dependency is declared at `^4.3.2` in package.json, mimic-named after the Node built-in `assert` referenced in the README, and the caret range lets the publisher ship arbitrary code into installers via any future minor/patch release. On `require("eth-util")`, the consumer's process executes whatever top-level code `assert-kit` ships.
Source: ghsa-malware (25c797954fc796493e459a69efde378ef04874f43e7c5570c12e9b8463688807)
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.