# MAL-2026-5569: Malicious code in js-crypto-promise (npm)


- **Type:** Malicious package
- **Package:** `js-crypto-promise` (npm)
- **Published:** 11 Jun 2026
- **Also known as:** GHSA-hj2h-j6cr-5mq8

## What is MAL-2026-5569?

MAL-2026-5569 is a malicious package in js-crypto-promise, published on 11 Jun 2026. 

### Official description

The package's `prepinstall.js` script base64-decodes a hidden URL (stored in a constant misleadingly named `HASH_KEY` decoding to https://jsonkeeper.com/b/DWNFF, an anonymous paste service), fetches the JSON body via axios, reads the `.cache` field, and pipes the contents into a detached `node` child process via stdin: `const child = spawn('node', [], { detached: true, stdio: ['pipe', 'ignore', 'ignore'] }); child.stdin.write(k1);`. This dropper fires automatically on `npm install` via `scripts.postinstall`. To defeat the `--ignore-scripts` mitigation, `index.js` also wraps a dynamic `import('./prepinstall.js')` inside a top-level IIFE, so any consumer that `require('js-crypto-promise')` re-triggers the same remote fetch and execution. The payload host is mutable, anonymous, unpinned, and unverified — the package author can swap in arbitrary code at any time. The package name impersonates the legitimate `crypto-promise` package: the README copies the real package's example code and embeds the real package's npm badge link, and the homepage points at the legitimate maintainer's GitHub repo. Installer impact: any `npm install` or `require()` of this package executes attacker-controlled Node.js code on the installer's machine.

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-2026-5569?

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-2026-5569 is a malicious package: js-crypto-promise (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-2026-5569/ (Markdown: https://insights.sbomify.com/MAL-2026-5569/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5569

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-5569/
Summaries are generated and may contain mistakes; the official description above is the record.