MAL-2026-5444 Malicious code in grateful-checkout (npm)
Malicious package
Published
MAL-2026-5444 is a malicious package: grateful-checkout (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-2026-5444/ (Markdown: https://insights.sbomify.com/MAL-2026-5444/index.md)
- Package
- grateful-checkout
- Registry
- npm
What is MAL-2026-5444?
MAL-2026-5444 is a malicious package in grateful-checkout, published on 9 Jun 2026.
Official description
On
npm install, the postinstall hook in src/canary.js performs a DNS lookup and an HTTPS GET to a serveo tunnel host (96e03fa6c292469a-172-245-86-254.serveousercontent.com/canary-install?pkg=...&ver=...), leaking the installer's source IP and the resolved package name/version to a third-party endpoint without consent. The package's README falsely claims that no data is collected or transmitted. The package additionally impersonates the API surface of an internal Exodus checkout-signing module (generateMnemonicSigningKeys, signDirectPaymentMultiChain, signCapture, signRefund, signCharge, signCancelSubscription) to land via dependency confusion against private name resolution. While self-described as a security research PoC, the behavior — uncontracted outbound network from a lifecycle hook to a researcher-controlled tunnel and namespace impersonation of a private package — is installer-harming regardless of intent.What should I do about MAL-2026-5444?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.