# MAL-2026-4738: Malicious code in zest-product (npm)


- **Type:** Malicious package
- **Package:** `zest-product` (npm)
- **Published:** 21 May 2026
- **Also known as:** GHSA-qm6m-33hv-fvwv

## What is MAL-2026-4738?

MAL-2026-4738 is a malicious package in zest-product, published on 21 May 2026. 

### Official description

On `npm install`, postinstall.js collects host identity and environment data (os.hostname(), username, process.cwd(), process.env values, plus shelled-out `whoami`/`hostname`/`id` via child_process.execSync) and ships it over the network. Outbound destinations include `https://app.interactsh.com` (an out-of-band interaction service commonly used for blind-exfiltration / SSRF beacons) and `http://lululemon.jfrog.io` (a JFrog endpoint referenced by hardcoded URL — consistent with a dependency-confusion attack targeting Lululemon's internal package namespace). Collected data is base64-encoded (Buffer.from(...).toString('base64')) before transmission via https.request. index.js additionally constructs a `curl -X POST` command interpolating `$(whoami)`, `$(hostname)`, and `id` and runs it via child_process.exec. The `99.9.0` version number combined with the lululemon.jfrog.io reference is the canonical dependency-confusion fingerprint: publish a public package with a name matching an internal one and a high version to win resolution. Installer harm: identity, environment variables, working-directory contents, and internal-network reachability data are leaked to attacker-controlled infrastructure on every install.

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-2026-4738?

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-2026-4738 is a malicious package: zest-product (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-2026-4738/ (Markdown: https://insights.sbomify.com/MAL-2026-4738/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-4738

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-4738/
Summaries are generated and may contain mistakes; the official description above is the record.