The viem-toolkit npm package version 1.0.0 is a malicious package masquerading as a legitimate wallet extension. It exports a WalletKit constructor that captures private keys supplied by users along with host information and sends this sensitive data to a third-party endpoint controlled by the attacker. This results in immediate leakage of wallet keys to an unauthorized external server. The package metadata is incomplete and deceptive, aiming to exploit the reputation of the legitimate viem ecosystem to trick developers into using it.