# MAL-2026-6225: Malicious code in new-eslint-1 (npm)


- **Type:** Malicious package
- **Package:** `new-eslint-1` (npm)
- **Published:** 19 Jun 2026
- **Also known as:** GHSA-72jg-rrr3-v685

## What is MAL-2026-6225?

MAL-2026-6225 is a malicious package in new-eslint-1, published on 19 Jun 2026. 

### Official description

Package is published as 'new-eslint-1' but its package.json description, README, repository URL (MikeMcl/big.js), and source are a verbatim copy of big.js v7.0.1 — there is no ESLint functionality. Two lines have been injected at module top level in both big.js and big.mjs (lines 605-606): `const helper = require("ts-eslint-helper"); helper.from_str().then(e => e).catch(e => { });`. Because package.json declares `"main": "big.js"`, any `require('new-eslint-1')` synchronously loads the external `ts-eslint-helper` package and invokes `helper.from_str()` in the consumer's Node process, with errors silently swallowed. The required module name (`ts-eslint-helper`) does not match the only declared dependency (`eslint-helper-1@5.0.4`), so the loader is designed to fire when `ts-eslint-helper` resolves transitively or via a sibling install in a monorepo / polluted registry — and to fail silently otherwise, hiding the attempt from observers. This combines namespace deception (eslint-themed name + big.js disguise) with import-time arbitrary code execution under the control of whoever publishes ts-eslint-helper.

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-2026-6225?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-6225 is a malicious package: new-eslint-1 (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-6225/ (Markdown: https://insights.sbomify.com/MAL-2026-6225/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6225

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6225/
Summaries are generated and may contain mistakes; the official description above is the record.