How to remove US-U.Openx.net from Safari

This is what worked perfectly for me:

To remove US-U.Openx.net from Safari (recommended by Norton.com)

Reset Safari

Start the Safari browser.

On the Apple menu bar, select History > Clear history > All History > Clear History.

When you clear the browsing history in Safari, it also clears the website data (such as saved passwords and other entries).

On the Apple menu bar, select Safari > Preferences > Extensions > Uninstall