Why does anyone think criminals won't be able to use the same system to steal bank account and credit card information, use it to launch other attacks or turn it into a massive spam-sending network?

Other large U.S.-based Banks declined to comment on whether they have faced similar attacks.

Having a botnet at your fingertips will cost you $225, and a tool that exploits a vulnerability on a banking site averages $740 and runs as high as $3, 000.