Back in April this year Bangladesh bank was targeted by cyber criminals who got away with around $80million and they would have stolen a lot more, they had tried to steal $1billion, if they hadn’t made a spelling mistake which was then flagged up by an employee and the fraudulent transactions stopped. The criminals targeted the SWIFT payment system, a system banks use to transfer billions of dollars every day. It is believed the attackers have been able to send fraudulent messages triggering money to be transferred into their bank accounts. You would be forgiven for thinking that this exploit would have been fixed straight after the Bangladesh bank attack but if appears more banks have been attacked using a similar attack.
For more on the recent attack: http://www.bbc.co.uk/news/technology-36284446