Advanced malware that allows full control over an ATM through a customised user interface detected.
An investigation by Trustwave's SpiderLabs performed an analysis of malware found installed on compromised ATMs in Eastern Europe. It found that the malware is able to capture magnetic stripe data and PIN codes from the private memory space of transaction-processing applications installed on a compromised ATM.
It revealed that the interface is accessible by inserting controller cards into the ATM's card reader. Analysts at SpiderLabs do not believe that the malware includes networking functionality that would allow it to send harvested data to other remote locations via the internet.
However they do believe that the malware allows for the output of harvested card data via the ATM's receipt printer or by writing the data to an electronic storage device (possibly using the ATM's card reader).
The analysts also discovered code that indicates that the malware could eject the cash dispensing cassette. They believe that what was identified was a relatively early version of the malware, and that subsequent versions have seen significant additions to its functionality.
Trustwave claimed that the malware is installed and activated through a dropper file by the name of isadmin.exe, aand that the binary contains a data resource named ‘packageinfo' which in turn contains the actual malware.
Once active, the malware intercepts ATM transactions by injecting code into targeted processes through the binary modification of these processes in memory. The first process targeted by the malware appears to be a system-messaging utility, while the other is a form of ATM software service.
Once it resides in the memory, the malware polls the transaction message queue looking for track 2 data from the current transaction. It can then perform a level of validation and manipulation against this track data to determine whether the transaction is the attacker's trigger or controller card or a valid transaction involving track data that the malware collects by recording it in a file.
Trustwave said: “Given the impact this malware can have on an infected ATM environment, Trustwave highly recommends all financial institutions with ATMs under management perform analysis of their environment to identify if this malware or similar malware is present.