eth-batchernpm
eth-batcher is a confirmed malicious npm package (MAL-2026-14208) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in eth-batcher (npm)
What this malware does
index.js is a verbatim copy of an unrelated Mongoose LeanHooks Plugin with a ~149 KB obfuscated Function(...) payload concatenated onto the module.exports line. On require(), the payload constructs and executes code decoded from a hex byte table via an XOR/rotation decoder. The advertised purpose in package.json (Ethereum JSON-RPC batching) does not match the shipped code, which contains no Ethereum or Web3 logic — the mismatched benign source acts as a cover for the appended dropper. Any process that imports this package executes the decoded payload at load time.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for eth-batcher (version 1.0.0).
If you installed it — respond
Remove eth-batcher 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-batcher 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
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks eth-batcher-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.