My memory of this movie is very vague, which is scary considering I saw it only a few years ago.

I believe it was a zombie movie (maybe vampires? Or people with some weird virus?) that took place either up north or somewhere in the winter. I don't remember a lot of it at all sadly. I remember the zombies could run superfast (think 28 days later). The group of survivors/noninfected were holed up in some building in this abandoned town that was swarming with them.

That's the best I can come up with - I really don't remember a lot of it. It wasn't very old though... it's a shot in the dark, but anyone?

Haha never mind, I figured it out.
It was vampires. 30 days of night was the movie I was thinking of.