Flash, Silverlight and Internet Explorer were heavily targeted by hackers in February, according to a report by cybersecurity firm NSS, probably because exploit techniques discovered in November made them easier to crack.
The source code and back-end data for the Rig exploit kit were also leaked online last month, "which gives interesting insight into which applications and operating systems were targeted," NSS noted. Rig targets Flash, Silverlight and Internet Explorer, among other applications.
Cryptowall, a particularly nasty threat that encrypts the data on a target computer with a virtually uncrackable password that won't open unless the user pays ransom, also saw a surge of activity.
Hacker prefer to target certain combinations of operating systems and applications, according to NSS. Rig focuses on Java, Flash, Silverlight and Internet Explorer running on Windows 7, 8.1 and XP.
The NSS study also found that Hong Kong topped the list of locations hosting hackers' command and control servers, followed by South Korea, Russia and the United States.
