Which versions of win-build-utils are malicious?

The following npm versions of win-build-utils are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate win-build-utils if I installed it?

win-build-utils is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed win-build-utils — how do I know if it already compromised me?

If win-build-utils 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 win-build-utils part of a known attack campaign?

Yes — win-build-utils is associated with the RLMA-2026-05653, IN-MAL-2026-013032, RLUA-2026-06552 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 win-build-utils 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 win-build-utils (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging win-build-utils across your stack and pipelines.

Malicious package

win-build-utilsnpm

win-build-utils is a confirmed malicious npm package (MAL-2026-10905) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in win-build-utils (npm)

MAL-2026-10905

Immediate action

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

npm uninstall win-build-utils

What this malware does

The package name suggests a Windows build helper utility, but no concrete behavioral evidence is available to confirm or refute installer-side risk. No exfiltration, install-time fetch, credential access, or other attack-class behavior was observed. The package warrants human review to confirm contents and intent before issuing a public verdict.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

7f6c85194f2cc39ade690b7b9a94332657b6251b638d8908080bedf5b98d908f

03bd3facc00c36861223058a572fbaa888d815a06c7b309c44639c544c65f1d9

26e3dee77c0d7ff1e6dd5b799e65f48cb574e70615a72d3631410e713de15b7d

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for win-build-utils (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging win-build-utils across your stack and pipelines.
If you installed it — respond
win-build-utils is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If win-build-utils 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 win-build-utils 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. win-build-utils on npm has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-05653IN-MAL-2026-013032RLUA-2026-06552

References

Credits

Amazon Inspector · finder
ReversingLabs · finder

Detect & block this

O3 blocks win-build-utils-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

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