The best way to go about doing this is to get a Free Website Security Scanner. This will give you the ability to scan your site for any possible security issues and will then help you in determining which of the various ways you can get these problems fixed will be the best course of action. You can use these scans to determine what sort of things are causing the problems, as well as which sites and web pages you need to clean up and which pages need to be updated and improved on.
Free website scanners will help you find out if there are any viruses on your site or if there is some sort of
