In today's world , where threats from the web are evolving at  such a brisk rate that even for the security vendors like Sophos , McAfee Symantec , TrendMicro etc its almost impossible to detect and remediate and protect machines from getting infected , the reason being that the malware writers are now focused on Steath techology i.e being undetected commonely known as rootkits, they can get the critical information of yours especially the Bank A/C info w/o you knowing it and your Anti-virus security product unable to detect it and left as a mere spectator at that point.

So how to check if you are exposed to risk or your machine has been compromised.Here is a video from which you can easily check-out if your system have hidden threats residing or not Peter Giannoulis of TheAcademyPro.com is demonstrating how we can do it easily.

So before opening any Banking website you can check if any threat is not active.

 
src: http://searchsecurity.techtarget.com

Do keep in mind that it doesn't mean we don't need to install any anti-virus , its very essential to have one best out of the above mentioned.