they are on this link here. They are usually difficult to remove also but in order to help you we would need a lot more specific information than what you have given.
What are root kits? Do they cause damage and can they hack your PC? The reason I am asking that is because my anti-spy ware is saying I have one on my PC. Plus for some reason it cannot be removed by my anti-spyware. I have the web root anti-spyware software.