Which versions of checkout-use-notifications are malicious?

The following npm versions of checkout-use-notifications are flagged malicious: 35.6.1. Treat any of these as compromised.

How do I remediate checkout-use-notifications if I installed it?

Remove checkout-use-notifications 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 checkout-use-notifications — how do I know if it already compromised me?

If checkout-use-notifications 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-use-notifications part of a known attack campaign?

Yes — checkout-use-notifications is associated with the IN-MAL-2026-015171 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-use-notifications 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-use-notifications (version 35.6.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging checkout-use-notifications across your stack and pipelines.

Malicious package

checkout-use-notificationsnpm

checkout-use-notifications is a confirmed malicious npm package (MAL-2026-12602) that executes malicious code on install (malicious version 35.6.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in checkout-use-notifications (npm)

MAL-2026-12602

Immediate action

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

npm uninstall checkout-use-notifications

What this malware does

On require of the package, index.js unconditionally loads shim.js, which fetches a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev) with a DNS TXT-record fallback channel via sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. Hostnames are assembled at runtime by joining split string fragments to evade static detection. The fetched payload is written to /tmp or %TEMP% under disguised names (.cache<rand>, dotnet_diag_<rand>.exe), chmod 0755 on Unix, and spawned detached via /bin/sh -c or cmd with stdio ignored. The DNS fallback base64-decodes numbered TXT chunks to reconstruct the payload when HTTPS fetches fail. An anti-re-run stamp gates repeated execution. The delivery infrastructure, string-split hostname obfuscation, disguised on-disk filenames, and DNS covert channel are canonical malicious dropper fingerprints.

Malicious versions

1 flagged

35.6.1

Indicators of compromise (SHA-256)

1a9b7cb00a4aac61795c81a085319cb8b0ac0aff1350a0dafddb4ef31d25a15f

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 checkout-use-notifications (version 35.6.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging checkout-use-notifications across your stack and pipelines.
If you installed it — respond
Remove checkout-use-notifications 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 checkout-use-notifications 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-use-notifications 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-use-notifications on npm has been identified as a malicious package (version 35.6.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015171

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks checkout-use-notifications-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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