How did you manage to do that.All banks have secure networks. If worried maybe inform your bank in case of any illegal transactions do occur. Like Diodorus Siculus says change your passwords and keep your fingers crossed.As some banks may not cover you for using an un-secure network or if you do not have proper security on your computer. So far I have not heard of any banks doing this,but a few have threatened to do it.
It only appears when you start to type on a web page. If you type a letter and look at where it lives on your screen, you will see that what it types appears to be garbage. The site that you are on is the only site that receives the true words as typed.