Which versions of checkout-todo-test are malicious?

The following npm versions of checkout-todo-test are flagged malicious: 35.5.9. Treat any of these as compromised.

How do I remediate checkout-todo-test if I installed it?

checkout-todo-test 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 checkout-todo-test — how do I know if it already compromised me?

If checkout-todo-test 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 checkout-todo-test part of a known attack campaign?

Yes — checkout-todo-test is associated with the IN-MAL-2026-015168 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 checkout-todo-test 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 checkout-todo-test (version 35.5.9). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging checkout-todo-test across your stack and pipelines.

Malicious package

checkout-todo-testnpm

checkout-todo-test is a confirmed malicious npm package (MAL-2026-12597) that opens a backdoor for remote access (malicious version 35.5.9). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in checkout-todo-test (npm)

MAL-2026-12597

Immediate action

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

npm uninstall checkout-todo-test

What this malware does

On require of this package, index.js loads _platform.js, which asynchronously downloads a platform-specific binary from anonymous Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev), with a DNS-TXT covert-channel fallback that reassembles a base64 payload from numbered subdomain records under *.dl.wel1.ru. The destination hostnames are assembled at runtime by joining split string fragments to evade static analysis. The downloaded bytes are written to a temp path with a disguised name (.cache_XXXX on Unix, dotnet_diag_XXXX.exe on Windows), chmod 0755 on Unix, and executed via cp.spawn("/bin/sh", ["-c", fp + " &"], {detached:true}) or cmd.exe /c start /b. There is no hash or signature verification, and the hosts are not publisher-controlled infrastructure. The tarball also ships an unreferenced sibling module lib/telemetry.js (~81 KB) containing the same download→chmod→spawn pattern as latent staged code. The package presents its behavior as "telemetry/analytics" with env-var opt-outs, but the runtime-reconstructed C2 destinations, DNS covert channel, and disguised on-disk artifacts are inconsistent with legitimate telemetry.

Malicious versions

1 flagged

35.5.9

Indicators of compromise (SHA-256)

a87cb6c1e9ab39c21cd5d1031cadd2c192f86aaa337a62a7476657d5ee3f7f39

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 checkout-todo-test (version 35.5.9). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging checkout-todo-test across your stack and pipelines.
If you installed it — respond
checkout-todo-test 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 checkout-todo-test 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 checkout-todo-test 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. checkout-todo-test on npm has been identified as a malicious package (version 35.5.9 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015168

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks checkout-todo-test-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

Explore

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