It's frequently said that cybersecurity is an arms race, with defenders constantly adapting to attackers, and attackers finding ways to better evade their target's defenses.

For malware in 2012, the analogy is an apt one. Malicious programs continually evolved in 2012, whether using new technical approaches to infection, establishing novel business models or demonstrating the vulnerability of areas thought unrelated to cybersecurity. Flashback demonstrated that the Mac OS X had become a viable target for cybercriminals, while the Blackhole Exploit Kit refined the crime-as-a-service business model.

Malware also became a tool of nations in 2012, in many cases aimed at gathering intelligence in the Middle East. While previous years had hinted that nation-states would develop malware as one weapon in their arsenal, half of this year's list of malware was used for political aims.