Block bad referers
What is a referrer?
When you type the address of a site in the address bar of the browser, there is no referer, it's a direct access.
What is the "Spam Referer"?
The "spam referrer" is a technique of link spamming in order to make a site appear in the logs or statistics as a referrer site.
How to block Bad Referers?
Add an address per line in the Referers List section.