# MAL-2026-18187: Malicious code in simplewave (npm)


- **Type:** Malicious package
- **Package:** `simplewave` (npm)
- **Published:** 22 Oct 2026

## What is MAL-2026-18187?

MAL-2026-18187 is a malicious package in simplewave, published on 22 Oct 2026. 

### Official description

simplewave@0.0.2 declares a postinstall script in package.json that runs an inline Node command performing an HTTP GET to a subdomain of oast.fun with the installer's os.hostname() embedded as the leftmost DNS label. oast.fun is the public Interactsh out-of-band interaction server, used to receive exfiltrated data via DNS/HTTP callbacks. The beacon fires unconditionally on npm install, with no caller consent or configuration. The shipped index.js is a trivial stub providing no advertised functionality, so the manifest-level beacon is the package's entire effect. The host identifier of every machine that installs the package is delivered to a third-party OOB collector controlled by whoever provisioned the oast.fun subdomain token.

## What should I do about MAL-2026-18187?

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-2026-18187 is a malicious package: simplewave (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-2026-18187/ (Markdown: https://insights.sbomify.com/MAL-2026-18187/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-18187

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-18187/
Summaries are generated and may contain mistakes; the official description above is the record.