Here is a thread that is showing you what happens when you do get a virus with a wallet stealer.
It plants copy and paste of someone's wallet address so when you think your sending to you address or another's you are sending it to the scammer's btc address.
http://bitcointalk.org/index.php?topic=1794944This is just a taste of what they can do.
It gets worst mister trust me it gets much worst than this invention from 'script kiddies' just messing with their mum's computer.

My bid condition was he sends me the login information first and I verify the withdrawal will be honored by the casino. He sent me a link to a ZIP (only an idiot would open that) so I marked him with negative. You don't need to lecture me on common sense.