Financial security

It looks like a few Russian hackers have just pulled off the biggest bank heist ever.

The numbers are shocking: hundreds of millions of dollars were stolen from 100 banks in 30 countries. The exact amount is unknown at this point. On top of that, the banks could lose possibly hundreds of millions more in related costs. And it all went mostly unnoticed until sometime last year.

On Monday, Russian cybersecurity firm Kaspersky released its report painting a startling picture of a worldwide operation that infiltrated major banks and turned ATMs into cash-spewing zombies.

 What we know about the bank hacking ring - and who's behind it