Just use a whitelisting hardware firewall for all financial work and be done with it. Dedicate a laptop to the work and put it behind said firewall. If Flame was in the wild for years then all the bullshit blacklisting security industries' best stuff is a complete waste... I knew that before Flame was discovered but I didn't realize it was that big of a waste....
Don't overlook - which countries may have produced Flame and who are their allies - which countries it was targeted at and who are their allies - which governments are actual and likely clients of the respective anti-virus companies
no, don't overlook how long it was in the environment before it was found... if it was out there for years then hundreds of others are out there right now.
I've used (free and paid for corporate) Microsoft Security Essentials exclusively personally and on client's machines and no one has ever had a problem. A good firewall and a head on your shoulders is much more reliable than paid or unpaid antivirus. These days you have no excuse to get a virus on your main machine. If you think something is suspect just open it up in a virtual-machine. VMware player is free as well as a slew of other virtual machine hosts that run on Windows or Mac. They are perfect for unknown attachments, porn, shady internet browsing, emails from Nigeria, etc. Build the VM, take a snapshot of it (make a copy essentially) and if you blow it up just roll it back or delete it and turn on a new one. All this talk about 3rd party anti virus and spyware is funny... Wait until Windows 8 and Server 2012 is mainstream. The AV will be integrated into Windows and pretty much anything else will be "in addition" or "supplementary".
This is what I do with about just any software out there including windows 7. By the way you don't need to enter a valid email... just something like sdfsdfsdfdf@sdasdasd.com will work. And.. Kas. is awesome.