# MAL-2026-5506: Malicious code in argoncrypt (npm)


- **Type:** Malicious package
- **Package:** `argoncrypt` (npm)
- **Published:** 10 Jun 2026
- **Also known as:** GHSA-h3m2-g8jh-9p37

## What is MAL-2026-5506?

MAL-2026-5506 is a malicious package in argoncrypt, published on 10 Jun 2026. 

### Official description

On require, index.js spawns a detached, unref'd Node child running lib/initializeCaller.js. That file decodes a base64-disguised URL (https://tomato-brunhilda-40.tiiny.site/index.json), fetches the response, and invokes it via `new Function.constructor('require', response)(require)` — granting the fetched code full Node capability with access to `require`. The destination is an anonymous free static-site host with no pinning, hash check, or signature verification; the fetch is retried up to 5 times. The C2 URL and HTTP header values are hidden as base64 strings stored under fake `process.env.DEV_*` defaults to evade casual review and string-search. The package additionally masquerades as a pino logger transport (exports `module.exports.pino`, ships a `smoke:pino` script, references a non-existent `./pino` module) despite a name unrelated to logging — a cover story for the dropper. Any developer or build system that installs and imports argoncrypt will silently execute attacker-controlled code with full host privileges.

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-2026-5506?

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-2026-5506 is a malicious package: argoncrypt (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-2026-5506/ (Markdown: https://insights.sbomify.com/MAL-2026-5506/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5506

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-5506/
Summaries are generated and may contain mistakes; the official description above is the record.