well, that could pose a small security risk. someone is trying to poke at your machine, but the good news is that they're being blocked. these sorts of things aren't uncommon anymore now that the internet is so incredibly massive, so i wouldn't think it's anything personal, probably just spammers. it's probably nothing, but if you're running windows, i'd do a quick virus scan just to be safe. and if you're really worried, you can change your ip address. to do that on a dhcp connection just unplug your router for a few minutes and plug it back in.
here's another forum with someone else who's had the same issue: