# MAL-2026-6673: Malicious code in anthropic-toolkit (npm)


- **Type:** Malicious package
- **Package:** `anthropic-toolkit` (npm)
- **Published:** 30 Jun 2026
- **Also known as:** GHSA-c7v6-f7mc-9crv

## What is MAL-2026-6673?

MAL-2026-6673 is a malicious package in anthropic-toolkit, published on 30 Jun 2026. 

### Official description

anthropic-toolkit@0.1.1 is a typosquat against the @anthropic-ai/sdk ecosystem. The package ships no library code — its declared `main` (`dist/index.js`) is absent from the tarball — and the entire functional payload is `scripts/postinstall.js`, which runs automatically on `npm install`. On install the script collects host and user identifiers (`os.hostname()`, `os.userInfo()`, `os.platform()`, cwd), parses `~/.gitconfig` and `~/.config/git/config` for `user.email`, walks `.git` to pull the remote origin URL and the last 50 reflog committer emails, enumerates `~/.ssh/*.pub` to extract key-comment emails, reads `~/.aws/config` for profile names, reads `~/.config/gh/hosts.yml` for the authenticated GitHub user, reads `~/.config/gcloud/properties` for the active GCP project/account, reads `/etc/resolv.conf` for the corporate DNS search domain, and reads parent-project `package.json` metadata plus CI provider env. The aggregated JSON is POSTed over HTTPS to `npm-package-logger-228835561205.europe-west1.run.app`. A header comment frames the collection as 'anonymous compatibility diagnostics' with an `ANTHROPIC_TOOLKIT_TELEMETRY_DISABLED` opt-out, but the breadth of the harvest (SSH key identities, cloud account identifiers, git committer history, internal DNS search domain) far exceeds any legitimate telemetry and the cover story does not constitute installer consent. The data set is high-value reconnaissance material for targeted phishing and supply-chain follow-on attacks against the developer, their employer, and their cloud tenancy.

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-2026-6673?

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-2026-6673 is a malicious package: anthropic-toolkit (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-2026-6673/ (Markdown: https://insights.sbomify.com/MAL-2026-6673/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6673

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6673/
Summaries are generated and may contain mistakes; the official description above is the record.