Which versions of bigops-eslint are malicious?

The following npm versions of bigops-eslint are flagged malicious: 35.9.5. Treat any of these as compromised.

How do I remediate bigops-eslint if I installed it?

Remove bigops-eslint 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 bigops-eslint — how do I know if it already compromised me?

If bigops-eslint was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Is bigops-eslint part of a known attack campaign?

Yes — bigops-eslint is associated with the IN-MAL-2026-011520 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 bigops-eslint across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for bigops-eslint (version 35.9.5).

Malicious package

bigops-eslintnpm

Advisory published Aug 5, 2026Updated Aug 5, 2026

bigops-eslint is a confirmed malicious npm package (MAL-2026-12061) that executes malicious code on install (malicious version 35.9.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bigops-eslint (npm)

MAL-2026-12061

Immediate action

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

npm uninstall bigops-eslint

What this malware does

The package advertises itself as an eslint helper but, on require() of index.js, unconditionally loads helpers.js which fetches an OS-specific executable over HTTPS from string-concatenated hardcoded hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, and sdk/ext/pkg/net.dl.wel1.ru), with a DNS-TXT chunked base64 fallback channel over c.<domain> and numbered TXT records. The fetched bytes are written to /tmp or %TEMP% under disguised names (.cache<rnd>, dotnet_diag_<rnd>.exe), chmodded 0755, and spawned detached via /bin/sh -c '<path> &' or cmd.exe /c start /b, with.unref() to survive the parent. Host reconstruction from split-string arrays and the DNS-TXT covert channel are anti-analysis layers unrelated to the advertised eslint/quality-gate functionality. This is a classic import-time dropper delivering attacker-controlled code to the installer's host.

Malicious versions

1 flagged

35.9.5

Indicators of compromise (SHA-256)

8a2b7c0da202027f856d059a571a04e01fd992845a158dcd01dfcd1bea4000bb

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bigops-eslint (version 35.9.5).
If you installed it — respond
Remove bigops-eslint 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 bigops-eslint was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. bigops-eslint on npm has been identified as a malicious package (version 35.9.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-011520

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks bigops-eslint-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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