A hacker has discovered how to force cash machines to dispense money by hijacking the computers inside them.
Barnaby Jack spent two years tinkering with machines he bought online, they were standalone dispensers, the type seen in front of convenience stores, rather than the ones in bank branches.
His goal was to find ways to take control of them by exploiting weaknesses in the computers that run the machines.
He showed off his results today in Las Vegas at the Black Hat conference, an annual gathering devoted to exposing the latest computer-security vulnerabilities.
His attacks have wide implications because they affect multiple types of machines and exploit weaknesses in software and security measures that are used throughout the industry.
His talk was one of the conference's most widely anticipated, as it had been scrapped a year ago over concerns that fixes for the machines would not be in place in time. He used the extra year to craft more dangerous attacks.
Jack, who works as director of security research for Seattle-based IOActive, showed in a theatrical demonstration two ways he can get machines to spit out money:
-- He found that the physical keys that came with his machines were the same for all machines of that type made by that manufacturer. He figured this out by ordering three machines from different manufacturers for a few thousand dollars each. Then he compared the keys he got to pictures of other keys, found on the Internet.
He used his key to unlock a compartment in the ATM that had standard USB slots. He then inserted a program he had written into one of them, commanding the ATM to dump its vaults.
-- Jack also hacked into machines by exploiting weaknesses in the way ATM makers communicate with the machines over the internet. Jack said the problem is that outsiders are permitted to bypass the need for a password. He didn't go into much more detail because he said the goal of his talk "isn't to teach everybody how to hack machines. It's to raise the issue and have ATM manufacturers be proactive about implementing fixes."
The remote style of attack is more dangerous because an attacker does not need to open up the machines.
It allows an attacker to gain full control of the machines. Besides ordering it to spit out money, attackers can silently harvest account data from anyone who uses the machines. It also affects more than just the standalone machines vulnerable to the physical attack; the method could potentially be used against the kinds of machines used by mainstream banks.