Symantec's Liam OMurchu handles Trojans every day through his work at Symantec.
But the Trojan.Silentbanker, which affects all versions of Windows since Windows 95, stood out as one of the most smartly build and therefore dangerously effective Trojans in the wild.
"This Trojan downloads a configuration file that contains the domain names of over 400 banks. Not only are the usual large American banks targeted but banks in many other countries are also targeted, including France, Spain, Ireland, the UK, Finland, Turkey - the list goes on." writes OMurchu.
It can successfully intercept account information that requires two-factor authentication before it is encrypted by the browser and sending it to the hacker's inbox.
According to Symantec's database, the Trojan horse can perform up to 11 different tasks ranging from capturing screenshots of websites and sending that to the attacker, to recording the user name and passwords.
Additionally, the Trojan horse can also update itself on a regular basis to continually evade antivirus application and uses both Firefox and Internet Explorer to commit its crimes.
The Security firm urges companies to update their antivirus applications to keep this nasty thing at bay.