I have a Google Alert set up to check on what's happening with our company name. For the last few weeks I'll get alerts with our name or name and description listed. A click takes you to a malicious site that immediately tries to get you to click on a virus check or starts to install code. I've had to shut down the computer to stop it. These are different site, not the same one all the time, and different phrases.

1) Will this hurt my Google rank or SEO? I've been on page 1 for my main keywords for years. Recently my PageRank dropped to a 3 from a 4, but I gather that was some sort of adjustment because it happened to similar sites at the same time and I saw some posts about it.

2) What do I do to stop this? It is obviously being done with purpose, not randomly.

Thanks much for any help you can give me.