I'm having trouble with a few spammy sites that are autogenerating pages that include links. Unfortunately, one of the links they're using is to my website. So far, through trackbacks, I've been linked to at least five times from three different, very similar spam sites, so it's probably the same person. I had nothing to do with this. They're simply using keywords to generate their spam page that I'm ranking well for. There could be many more of these out there.
Of course, there's a huge Penguin problem here, and I'm wondering how to fix it before I get penalized for these spammy links. What should I do here? I don't really want to take down the page on my site that they're spamming, because it accounts for 1/3 of my traffic, but I'm not sure that would work anyway.
Any advice would be appreciated.