MAL-2026-10413 Malicious code in eth-base (npm)

The published lib/index.js contains ~60KB of obfuscated JavaScript appended after a copy of the legitimate web3.js web3-core-subscriptions module. On require(), the appended IIFE loads axios, issues an HTTPS request to a URL reconstructed at runtime from custom base-85 alphabets, and on a specific response constructs new Function('require', <remote-token>)(require) to execute attacker-supplied JavaScript in-process with full Node require access. The corresponding src/index.js is the clean upstream module, indicating the payload was injected only into the shipped build. The package name and description impersonate a web3.js helper (LGPL header still credits Fabian Vogelsteller <[email protected]>) while the repository field is empty. Consumers who require this package receive arbitrary code execution on the installing host at load time.

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.