> But the largest sums were stolen by hacking into a bank’s accounting systems and briefly manipulating account balances. Using the access gained by impersonating the banking officers, the criminals first would inflate a balance — for example, an account with $1,000 would be altered to show $10,000. Then $9,000 would be transferred outside the bank. The actual account holder would not suspect a problem, and it would take the bank some time to figure out what had happened.<p>Sounds like a badly designed system. Usually a bookkeeping system should only accept additions and subtractions, not have direct access to the amount number. Those additions and subtractions should be versionned. It might take a lot of resource and computing power to track that many accounts, but in my opinions, if google, the NSA and amazon have big datacenters, banks should too. I don't think they really have the proper infrastructure to secure something so important like account balance. I even think the government should invest money in securing those systems and places, since it's a nerve of the economy.<p>So either use up to date computing methods, or hire more accountant and use paper instead.