Which versions of claims-domain are malicious?

The following npm versions of claims-domain are flagged malicious: 35.6.7. Treat any of these as compromised.

How do I remediate claims-domain if I installed it?

Remove claims-domain from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.

I already installed claims-domain — how do I know if it already compromised me?

If claims-domain 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 claims-domain part of a known attack campaign?

Yes — claims-domain is associated with the IN-MAL-2026-015161 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 claims-domain 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 claims-domain (version 35.6.7). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging claims-domain across your stack and pipelines.

Malicious package

claims-domainnpm

claims-domain is a confirmed malicious npm package (MAL-2026-12613) that executes malicious code on install (malicious version 35.6.7). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in claims-domain (npm)

MAL-2026-12613

Immediate action

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

npm uninstall claims-domain

What this malware does

On require of the package, index.js loads _ext.js, which reconstructs destination hostnames from string-split arrays (e.g. ["oob-worker.cf99-9b3",".wor","kers.","dev"].join("")) to build URLs at oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, and oob-worker.cf102-baf.workers.dev, with a DNS TXT fallback to sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched platform-specific binary is written to /var/tmp or the Windows temp directory under disguised filenames (.cache_<hex>, dotnet_diag_<hex>.exe), chmodded to 0755, and spawned detached via /bin/sh -c or cmd /c start. The child_process module and fs.chmodSync API are also referenced through string concatenation (require("child_" + "process"), fs["chmod" + "Sync"]) alongside cover-story comments describing the routine as an analytics/telemetry SDK. The package's advertised purpose (a claims-domain library) does not require fetching or executing native binaries from anonymous Cloudflare Workers subdomains, and the delivery is unpinned, unhashed, and obfuscated.

Malicious versions

1 flagged

35.6.7

Indicators of compromise (SHA-256)

f75c174b3db5e2480eabc7c7f8ab5e8366737fac8e76086da13f8acac6545813

Detection & response playbook

Malicious package

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for claims-domain (version 35.6.7). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging claims-domain across your stack and pipelines.
If you installed it — respond
Remove claims-domain from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If claims-domain 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 claims-domain 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. claims-domain on npm has been identified as a malicious package (version 35.6.7 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015161

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks claims-domain-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.

Malware detection Runtime egress monitoring

Explore

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