How do these malwares exactly work? During investigation of the cases of breaches, CISCO security solutions have discovered the working mechanism a new malware family which has been nicknamed PoSeidon malware.
The infection of the PoS system possibly arises from a keylogger which after getting installed deletes the profile log in information i.e passwords stored on the system. This forces the user to type down the information which gets recorded by the keylogger and sent back to the server which can then access the system remotely to infiltrate it with the Loader malware to steal card information.
What the Loader does is, it tries to get itself installed in the PoS system as a service that is run as Winhost, so that it can survive reboots of the system. This step is called persistence by which it maintains hold on the system. It then connects to the hardcoded command and control servers, which then sends the second executable part of the malware called the FindStr.
It also simultaneously installs another keylogger. FindStr goes through data on the infected system to look for number sequences that start with 6, 5, 4 with a length of 16 digits (Discover, Visa, Mastercard) or 3 with a length of 15 digits (AMEX).
It then runs the Luhn algorithm to verify whether its card information or not and sends the information along with data from keylogger to the exfiltration servers from where it can be harvested for further usage.
The malware can also update itself depending on communication from external server. Further investigation shows that developers are working to use these in other newer projects.Faced with such persistent threats organizations need to be vigilant and adopt a threat-centric approach to provide security during the full attack continuum – before, during, and after an attack.