Which versions of neverthrow-core are malicious?

The following npm versions of neverthrow-core are flagged malicious: 1.1.2. Treat any of these as compromised.

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

neverthrow-core is a typosquat — you almost certainly intended a legitimately-named package. Remove neverthrow-core, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.

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

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

Yes — neverthrow-core is associated with the IN-MAL-2026-018398 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-core 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-core (version 1.1.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging neverthrow-core across your stack and pipelines.

Malicious package

neverthrow-corenpm

neverthrow-core is a confirmed malicious npm package (MAL-2026-14283) that typosquats a legitimate package to trick installs (malicious version 1.1.2). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in neverthrow-core (npm)

MAL-2026-14283

Immediate action

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

npm uninstall neverthrow-core

What this malware does

[email protected] is a typosquat of the popular neverthrow library. Its package.json declares a preinstall script node -e "require('./dist/index.cjs.js').bcryptInstall()" that auto-runs on every npm install. The invoked bcryptInstall function inside the CJS bundle fetches https://www.dropbox.com/scl/fi/${sha}/bcrypt-all-platforms.tar.gz, streams the archive to disk via Readable.from/pipeline, chmods the extracted files, and executes them using spawnSync and createRequire. The Dropbox path is anonymous and mutable, is not pinned to a package version, and no signature or hash verification is performed; Dropbox is unrelated to the legitimate neverthrow publisher. The dropper is only present in the CJS bundle — the sibling ESM build (dist/index.es.js) does not contain bcryptInstall, hiding the payload from consumers who inspect the ESM entrypoint. Package metadata (repository, homepage, author) is copied from supermacro/neverthrow to impersonate a first-party companion package.

Malicious versions

1 flagged

1.1.2

Indicators of compromise (SHA-256)

da6f9496a578c672b465944e85c471edd19ce837ec7693d472d6c4a3ea3733a7

Detection & response playbook

Typosquat

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for neverthrow-core (version 1.1.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging neverthrow-core across your stack and pipelines.
If you installed it — respond
neverthrow-core is a typosquat — you almost certainly intended a legitimately-named package. Remove neverthrow-core, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If neverthrow-core 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-core 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-core on npm has been identified as a malicious package (version 1.1.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-018398

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks neverthrow-core-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

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