By the end of 2008 it is estimated that 52% of American households will have a computer network set up, allowing more than one computer to access the internet at any given time. Defined in it’s simplest form, a computer network is two or more computer systems linked by either a cable or a wireless device, sharing files or internet access. If there is no central server in use then the network is called a peer to peer network, of P2P, in which all computers are equal. This is also known a workgroup, a name coined by Microsoft.

Microsoft took a totally clean computer system and allowed it to be turned into a “zombie” for an experiment. Over only three weeks they noted that the zombie computer received over 5 million connection requests; these all came from spammers around the world. It also received 18 million spam messages, sent by 13,000 different websites. This was all to a single computer. A zombie is a computer infected with any form of malicious software, also known as “malware”, that can be used by the attacker to control aspects of the computers behavior remotely.