One of My Core Plugins

Until Google solves the spam traffic issue, I’ll be using this plugin on every WordPress website. Does it take care of all of the spam traffic? No. It takes care of the spam bots that visit your site.

There are ghost referrers that need to be taken care of as well, and no WordPress plugin can do that. Ghost referrers never visit the site with the Google Analytics code. For that, you need to set up a Google Analytics filter that includes only valid host names.

If you want to read more about how to solve the spam traffic issue, here is a detailed article on getting rid of the spam in Google Analytics.