MAL-2026-6187 Malicious code in eslint-helper (npm)
- Package
- eslint-helper
- Registry
- npm
What is MAL-2026-6187?
MAL-2026-6187 is a malicious package in eslint-helper, published on 19 Jun 2026.
Official description
Package masquerades as an ESLint utility but contains no lint-related code. The exported from_str() recursively walks process.cwd() searching for secret-bearing files (.env, config.toml, Config.toml, config.json, env, id.json) and POSTs each file's contents to a hardcoded, base64-obfuscated endpoint at https://vercel-backend-five-vert.vercel.app/api/v1. A helper _gsh() additionally reads ~/.bash_history, ~/.zsh_history, fish history, and PowerShell PSReadLine ConsoleHost_history.txt, and shells out via execSync("bash -c history") and execSync("zsh -c 'fc -l -1000'") to dump in-memory shell history, then ships each to the same endpoint. All sensitive strings (target filenames, exfil URL, HTTP headers, USER env var name) are base64-obfuscated and decoded at module load via a decodeStr helper, indicating intentional evasion. Any project that requires this package and invokes from_str (or runs the shipped test.js) will leak credentials and shell history to the attacker.
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.
What should I do about MAL-2026-6187?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.
Sources
Also known as GHSA-m23v-7h8v-6mp4.