# MAL-2026-5098: Malicious code in js-shared-modules (npm)


- **Type:** Malicious package
- **Package:** `js-shared-modules` (npm)
- **Published:** 31 May 2026
- **Also known as:** GHSA-57xw-xm2f-j2wc

## What is MAL-2026-5098?

MAL-2026-5098 is a malicious package in js-shared-modules, published on 31 May 2026. 

### Official description

package.json declares `"postinstall": "node poc.js"`, which fires automatically on every `npm install`. poc.js reads `os.hostname()`, hex-encodes it, and issues an HTTPS GET to `zcpesvvighyuzqlzkqgdydwp9jn54hfeg.oast.fun` (an Interactsh out-of-band callback host), exfiltrating the installer's hostname to a third-party canary. The package has no legitimate functionality — `index.js` is an empty `module.exports = {}` and the source banner self-identifies as a dependency-confusion proof-of-concept squatting a generic internal-style name (`js-shared-modules`) to shadow a private package. Any installer who resolves this public package leaks their host identity to the canary domain.

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.

The OpenSSF Package Analysis project identified 'js-shared-modules' @ 1.11.7 (npm) as malicious.

It is considered malicious because:

- The package communicates with a domain associated with malicious activity.

## What should I do about MAL-2026-5098?

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-2026-5098 is a malicious package: js-shared-modules (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-2026-5098/ (Markdown: https://insights.sbomify.com/MAL-2026-5098/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5098

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-5098/
Summaries are generated and may contain mistakes; the official description above is the record.