US Patent 9628508 Discovery of suspect IP addresses

A method of discovering suspect IP addresses, the method including, at a client computer: monitoring the computer for malware; on detection of malware, obtaining a list of IP addresses with which a connection has been made or attempted at the client computer within a preceding time frame; sending the list of IP addresses to a central server; and receiving from the central server a blacklist of suspect IP addresses to allow the client computer to block connections with IP addresses within said blacklist.