My router's firewall blocks NetBus scans all the time......basically, it's either an already-infected machine scanning for other machines to infect, or a "central" server looking for already-infected machines to remote-control them.

If your firewall is blocking them, you can either ignore them or you can grab the IP, identify the culprit using something like the third box down in the middle column (assuming it's working now), and report them to their ISP.