I occasionally get attempts from other countries trying to get into my system. Obviously to see if they can break in. But its likely fully automated to cycle through addresses like robocalls and see which ones respond. I forget the setting but see if your router responds to them. There are legit websites that scan all your ports and such for ping responses or if you are essentially blacked out. I am sure you already do this however. Also, if you did have torrents running somewhere then there is a period of time that other clients will remember you and attempt to see if it can continue downloading a certain file. So that is still something to check out.