ATMs work on older software and making them prone to hack attacks. Hackers recently are using USB sticks to install ATM machine with malware giving them the control and draw out cash as revealed by German researchers at Chaos Computing Congress on 28th Dec in Hamburg, Germany.
Hackers reportedly used USB sticks to install malware on ATMs in Europe, eventually controlling them to dispense cash. The ATMs were supported by Windows XP. The hackers installed the malware and patched up the security holes making their attempt unnoticed and giving them to attempt several times. The malwares gives direct access to the machines cash dispensing options.
The Countries and Banks attacked by such hackers are not revealed. Fortunately these malware seems not to extract PIN numbers and personal details of customers. Software updates and better malware security to be soon installed in ATM machines.
Developing a counter to these attacks needs time and expertise and is difficult as the hack is untraceable. Windows is the dominating OS in ATM, except Windows Linux are also used.