Another article from Zeljka Zorz for Help Net Security: A deadly campaign delivers Pony info-stealer followed by Cryptowall ransomware, based on an article from Heimdal Security’s Andra Zaharia. The data stealer Pony is installed on the victim’s PC and forwards credentials to the attackers’ C&C (Command & Control) servers: these username/password combinations are used to compromise legitimate servers by injecting a malicious script, used to send victims to other sites serving the Angler exploit kit (EK). Cryptowall 4.0 is installed on vulnerable systems.
Another article at Heimdal – The Evolution of Ransomware: Is Cryptowall 5.0 Around the Corner? – looks at the ransomware business model and speculates a little on how future versions of Cryptowall might be ‘improved’.