This should not be confused with Norton 360 which is a legitimate antivirus program (although if you need help removing Norton 360 to reinstall it or another antivirus program you may want to visit my antivirus removal tool list.)
What we are talking about this time is a rogue security application known as Antivirus 360. Like many other rogue security applications (wolves in sheeps clothing as I used to call them), Antivirus 360 may have installed itself on your system by way of a security flaw in your browser or some other less than admirable method. Such avenues include aggressive popup ad advertising after a system is infecting with a trojan such as vundo. It seems to be the successor to the Antivirus 2009 rogue application.