I have several websites that get daily around 5% of visits from spam referrers. There is one strange things I noticed about this referrers: they show in Google Analytics, bu
You can restrict access use .htaccess or by filtering ALL robot visits from being tracked by Google Analytics. If that doesn't work, setup Google Analytics filtering. More details on how to do that can be found here: http://www.wiyre.com/google-analytics-darodar-forum-spam-what-is-it/
They are Russian based but routing their spiders through China and the Philippines. Maybe it would be best to block the whole IP address at this point, they have multiple sub-domains.