web3-eth-utilnpm
web3-eth-util is a confirmed malicious npm package (MAL-2026-6325) that typosquats a legitimate package to trick installs (malicious version 6.2.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in web3-eth-util (npm)
What this malware does
Package name and metadata impersonate the legitimate @ethereumjs/util / ethereumjs-util packages: README is copied verbatim from the upstream ethereumjs project (and even instructs users to npm install eth-util), the contributor list and repository URL point at ethereumjs/ethereumjs-monorepo, but the package is published under a different name and ownership. The published dist/index.js (line ~57) contains require("assertcore") and package.json declares "assertcore": "^3.1.7" as a runtime dependency. The human-authored src/index.ts has no such import, and the browser build at dist.browser/index.js also omits it — the extra require is injected only into the Node-targeted build that ships in the npm tarball, so reviewers reading the GitHub source see clean code while npm install + require('web3-eth-util') silently loads the third-party 'assertcore' package in the consumer's Node process with full privileges. 'assertcore' is not part of the legitimate @ethereumjs/util sources and resembles a typosquat of the standard 'assert' module. The combination — brand impersonation of a widely used Ethereum utility package, source/dist divergence hiding the injection from GitHub readers, and a require-time pull of an unrelated third-party package — is a dependency-chain dropper pattern that delivers attacker-controlled code to anyone who installs and imports this package.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for web3-eth-util (version 6.2.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging web3-eth-util across your stack and pipelines.
If you installed it — respond
web3-eth-util is a typosquat — you almost certainly intended a legitimately-named package. Remove web3-eth-util, 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 web3-eth-util 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 web3-eth-util 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
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks web3-eth-util-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.