Which versions of neverthrow-js are malicious?

The following npm versions of neverthrow-js are flagged malicious: 2.0.0. Treat any of these as compromised.

How do I remediate neverthrow-js if I installed it?

neverthrow-js 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 neverthrow-js — how do I know if it already compromised me?

If neverthrow-js 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 neverthrow-js part of a known attack campaign?

Yes — neverthrow-js is associated with the IN-MAL-2026-017272 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 neverthrow-js 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 neverthrow-js (version 2.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging neverthrow-js across your stack and pipelines.

Malicious package

neverthrow-jsnpm

neverthrow-js is a confirmed malicious npm package (MAL-2026-13706) that opens a backdoor for remote access (malicious version 2.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in neverthrow-js (npm)

MAL-2026-13706

Immediate action

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

npm uninstall neverthrow-js

What this malware does

Package [email protected] is a typosquat of the legitimate neverthrow library. package.json declares postinstall: node./dist/install.js, which runs automatically on npm install. The install script reconstructs the destination host and path from decoy arrays that mimic WordPress plugin metadata (filtered fragments yielding ecoferros.com and the path /wp-content/plugins/elementor/admin/dev-tools/index.php?req=verify) so the literal C2 URL never appears in source. It fetches a response, base64-decodes the body, and executes it via new Function("rq", parsed); nfu(require)(), passing require into the evaluated code so the remote payload has full Node capability on the installer's host. Execution is gated by a Date check for 2026-08-11 02:00:00 GMT. index.cjs.js reproduces the real neverthrow library to provide cover for the malicious install hook.

Malicious versions

1 flagged

2.0.0

Indicators of compromise (SHA-256)

2b58633ada4ac777e5a404d3fa38bc1e664cb4696ccffcfd010a9552b1605cbd

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 neverthrow-js (version 2.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging neverthrow-js across your stack and pipelines.
If you installed it — respond
neverthrow-js 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 neverthrow-js 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 neverthrow-js 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. neverthrow-js on npm has been identified as a malicious package (version 2.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-017272

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks neverthrow-js-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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