The firewalls at work show every attempted hack in real time. They are under constant bombardment. The firewalls are in "Stealth mode" which means that they don't have any response to an attack, so the attacker has no way of determining if there is actually a server at that IP address or not. There is no DNS name (URL) associated with the IP addresses on the firewalls. So these are all undirected attacks on random IP addresses.
The more you know about it, the more you realize just how SCARY a place the Internet really is.