# MAL-2026-6396: Malicious code in signup-embedder (npm)


- **Type:** Malicious package
- **Package:** `signup-embedder` (npm)
- **Published:** 24 Jun 2026
- **Also known as:** GHSA-8j4q-hx83-pfq9

## What is MAL-2026-6396?

MAL-2026-6396 is a malicious package in signup-embedder, published on 24 Jun 2026. 

### Official description

signup-embedder@99.99.99-poc2 ships preinstall.js and postinstall.js lifecycle scripts that auto-execute on `npm install`. preinstall.js collects hostname, current working directory, pid, Node version, platform/arch, user, and the list of environment variable names, and POSTs them as JSON to https://webhook.site/f83b073c-a04a-4ac5-8930-507051bd22f7; it also performs a DNS lookup against `<timestamp>.callbacks.report` for out-of-band confirmation. postinstall.js POSTs a similar host fingerprint (host, cwd, pid, node, platform) to the same webhook.site URL. The package's own description and comments label it a 'HubSpot dependency confusion PoC', and the 99.99.99-poc2 version is the canonical high-version shape used to win resolution against an internal package of the same name. Regardless of the 'PoC' framing, the package is published on the public npm registry and any installer (CI, developer machine, internal build) that resolves the name will have its host identifiers and environment variable names beaconed to an attacker-controlled collector and DNS sink, enabling internal-network mapping and follow-on targeting.

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-2026-6396?

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-2026-6396 is a malicious package: signup-embedder (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-2026-6396/ (Markdown: https://insights.sbomify.com/MAL-2026-6396/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6396

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6396/
Summaries are generated and may contain mistakes; the official description above is the record.