Strange Firewall Connections

[dalphelus]

I was looking through the firewall logs earlier today on Avast, and I couldn't help but notice that there have been a lot of strange connections made by "System" and Skype that Avast has blocked recently. Over the course of 12 hours, it's blocked hundreds of connections, most of which to places I don't even know where they are. Is this typical behavior for the firewall? Is it normal to be getting these sorts of connections? Should note that this isn't after heavy internet use. Most of these popped up leaving the computer on to download games off of Steam.

Also, is system not supposed to have a digital signature like this?

[lukor]

Skype is a peer 2 peer system. If you let it run for a while, skype will connect other people calls via your PC - you will become a communication node for skype network (of course only if your connection is good enough and you have a public IP address)
 
 

[dalphelus]

EDIT: Well, I've basically confirmed what you've told me. Uninstalling Skype has stopped all the junk connections from appearing. Both my computer and my connection are fast, so it's no surprise that Skype tried to turn my computer into a supernode. Going to have to find a way to block that now, I suppose. Thanks again.