# MAL-2026-4538: Malicious code in create-arnext-app (npm)


- **Type:** Malicious package
- **Package:** `create-arnext-app` (npm)
- **Published:** 26 May 2026

## What is MAL-2026-4538?

MAL-2026-4538 is a malicious package in create-arnext-app, published on 26 May 2026. 

### Official description

The package declares `"preinstall": "./.github/scripts/precheck"` in package.json, which invokes a 976KB stripped Linux x86_64 ELF binary hidden under `.github/scripts/`. The binary auto-executes unconditionally on `npm install`. Strings extracted from the binary reveal capabilities entirely inconsistent with the package's stated purpose (a `create-*-app` template scaffolder that copies a directory and runs `yarn`): PTRACE (anti-debug/process tracing), LIBBPF (kernel-level packet filtering/evasion), HTTP/1.1 with POST and DELETE methods, `https://` endpoints, RSA_PKCS1, Ed25519, and MLKEM (post-quantum key exchange) cryptographic primitives, and USERPROFILE host-identifier enumeration. The combination of kernel evasion + outbound HTTPS channel + KEM crypto + host-identifier fields is the fingerprint of an installer-targeted implant, not a precheck script. The binary is staged in `.github/scripts/`, an unusual location for runtime artifacts (typically reserved for CI configuration), which is consistent with concealment from casual review. The package name additionally resembles the legitimate `create-next-app` family, increasing the chance of confused-install. Installer impact: any developer running `npm install create-arnext-app` executes attacker-controlled native code on their machine with their privileges — equivalent to remote code execution.

This package was compromised as part of the IronWorm campaign. This campaign executes a malicious binary payload during installation via a preinstall hook. The payload is a Rust-built infostealer that targets developer environments, scanning for and harvesting credentials related to cloud providers, object storage, databases, source-control, package registries, and AI developer tools. It also targets cryptocurrency wallets, specifically injecting a malicious JavaScript hook into the Exodus desktop wallet to capture passwords and recovery phrases. Furthermore, the malware exhibits worm-like behavior by stealing GitHub and NPM credentials to push malicious updates to the victim's repositories and publish trojanized packages, and it uses an eBPF-based kernel rootkit to hide its processes and network connections on Linux systems.

## What should I do about MAL-2026-4538?

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-2026-4538 is a malicious package: create-arnext-app (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-2026-4538/ (Markdown: https://insights.sbomify.com/MAL-2026-4538/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-4538

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-4538/
Summaries are generated and may contain mistakes; the official description above is the record.