Two methods used by Stat spammers are
1) Bots visiting websites at random, generating a large number of hits on the front page, polluting web logs and Google Analytics.
2) Bots calling random Google Analytics IDs, thus polluting the statistics without even visiting the web site.
To remove these "false" visits from GA statistics, it is necessary to setup a number of filters to discard traffic from certain referrers and only accept valid hostnames.
I can do this for you based on a combination of valid hostnames and actual spammers which have polluted your statistics in the last month. I also have a list of some of the most obnoxious spammers worldwide, which I will set up in the filter as well.
Please note: I will create a new view in your Google Analytics account, using default settings but with the right filters to avoid spam. You will still have access to your standard view which will continue showing unfiltered data (or whatever it is setup to do). The new view will only include data from the time it is created and so the filters will not affect historical data.