If you're doing only online banking in that install, that would imply a limited set of sites you go to.
Simple soln is to type in (do not copy and paste what appears to be a correct link) the site for each bank, and when it comes up, bookmark it.
From then on, only use your bookmark and never use that install for anything else.
I'd also advise adding NoScript, Https-Everywhere and possibly Ghostery to your Firefox.
Have FF block images and cookies, then allow specifically only(!) those you need to make the bank sites work.
No need to mess with iptables.
Last edited by chrism01; 04-18-2013 at 09:33 AM.