Which versions of grateful-checkout are malicious?

The following npm versions of grateful-checkout are flagged malicious: 99.0.0-canary.1. Treat any of these as compromised.

How do I remediate grateful-checkout if I installed it?

grateful-checkout establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.

I already installed grateful-checkout — how do I know if it already compromised me?

If grateful-checkout was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is grateful-checkout part of a known attack campaign?

Yes — grateful-checkout is associated with the IN-MAL-2026-005118, IN-MAL-2026-005117 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find grateful-checkout across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for grateful-checkout (version 99.0.0-canary.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging grateful-checkout across your stack and pipelines.

Malicious package

grateful-checkoutnpm

Malicious code in grateful-checkout (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-5444

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall grateful-checkout

What this malware does

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.

Malicious versions

1 flagged

99.0.0-canary.1

Indicators of compromise (SHA-256)

09b2768ea8a2c0f9038e40a8109ae744ca38de664099bfa1fdf128790baeb67d

c2a9600ad3ee3fddd9f06425260c94edf660263800080787155a63d3e5212d12

Detection & response playbook

Backdoor / remote access

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for grateful-checkout (version 99.0.0-canary.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging grateful-checkout across your stack and pipelines.
If you installed it — respond
grateful-checkout establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If grateful-checkout was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks grateful-checkout before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. grateful-checkout on npm has been identified as a malicious package (version 99.0.0-canary.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-005118IN-MAL-2026-005117

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks grateful-checkout-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring