There are some very cynical people that say this really is a load of old cobblers. You have more chance of hitting 6 numbers on the Lotto, weekly for a year, than anyone getting onto a home computer. There also appears to be some confusion as to whether they actually exist and do what the AV companies say. Of course the paid for AV companies have suddenly.y identified this as a 'threat'.
Keep your AV up to date, run MS Antispy and a firewall if you need to. All of these are free and there is no need to pay for 'security' apps. Continue online banking without any worries, there are much, much easier ways to get bank details.