The story started when a scammer in the US "with no special equipment, reprogrammed the mini ATM in the corner to think it had $5.00 bills in its dispensing tray, instead of $20.00 bills". It was reported on CNN. However, as Wired reports:
How, exactly, he pulled off the swindle remained unreported. Curious, Dave Goldsmith, a computer security researcher at Matasano Security began poking around. Based on CNN's video, he identified the ATM as a Tranax Mini Bank 1500 series.
He then set out to see if he could get a copy of the manual for the apparently-vulnerable machine to find out how the hack worked. Fifteen minutes later, he reported success.
The manual explained how to put the ATM into operator mode, and also provided a list of the default passwords needed to manipulate the machine....