When I search my URL in quotes on google it brings up a bunch of spam sites that when clicked on bring up virus scanners saying your site is infected and such. My site PR lowered from PR4 to PR0 recently on its homepage and I think this might have something to do with it. You can see the results here: http://www.google.com/#q="catfoodreviews.com"&hl=en&start=10&sa=N&fp=KxYPMM6r3XA What should I do about this?
Those are probably scrapers who have copied your content. Are you trying to see what's been indexed for your site? That's the 'site:' bit. For example: http://www.google.com/#hl=en&q=site:catfoodreviews.com
You may want to disable your RSS feed. Some sites use an automated script to pull material from other sites, and the RSS feed makes it really easy for them to do that. The scammers just install an RSS to HTML script, and your site provides them with all the content they need.
May be worth it to you. Especially if they're higher ranking than the original site. May even want to check the IP addresses of the sites in question. They may all be hosted on the same server or with the same webhosts. One email to the host may get them all removed.
That might be the case that scrappers have copied your contents and got too many backlinks to their pages. Check out if this is situation.