Will ATMs be a New Target?

Over the past year and a half according to The Register, a family of data-stealing trojans has been discovered running through ATMs in Eastern Europe. These trojans have been evolving over time and have been fitted with a great deal of control. The main function of the malware replaces old techniques such as external card readers that were fitted over the existing card slot, and had the job of pre-reading, if you will, ATM and credit cards and storing the information as the card was being inserted. These ran on several batteries that were usually taped underneath the reader in between the actual ATM card reader and the fraudulent one. Now instead, the malicious software runs internally to collect card information and PIN numbers, as well as any other banking information that can be accessed by the user.
I t has also been found that this malware also has the ability to include master card and single use card functionality. The master card can be inserted into the ATM to access the malware and gives the user many other abilities such as access to print outs of log information, print outs of the card information it had collected, or even the ability to make the machine dispense all of its cash. The single use cards would apparently be used by less trusted indiviuals such as mules, that would have a single purpose such as removing money and returning it to the bosses for a cut.
The real question in this situation is how did the malware get on these systems? ATMs are on strict security controled closed networks, and there is no access at the kiosk itself. This leads me to believe that these cases likely began as an inside job in order to get the malware onto the ATMs in the first place. Otherwise the hackers would have had to jump a lot of network hurdles to get their payload all the way to that point. Or, the security on these banking systems were sub-par, to say the least.