Paladin Log4j Immunizer is a browser extension designed to provide protection against Log4j websocket attacks. Developed by Upfort, this extension is available for the Chrome platform and is completely free to use.

The main purpose of Paladin Log4j Immunizer is to disable connections over WebSocket to localhost and private IP addresses, unless the initiator is also localhost or a private IP. By doing so, it significantly reduces the risk of Log4j exploits against services running on private networks and localhost.

With Paladin Log4j Immunizer installed, your browser is hardened against various threats, including drive-by websites, phishing landing pages, malicious HTML attachments, and malicious ads. This adds an extra layer of security, preventing your browser from being used as a beachhead for launching Log4j exploits against your company's internal web applications.