ESET Threat Blog
The year 2011 could be referred to as a year of growth in complex threats. Over the course of this year we witnessed an increase in the number of threats targeting the Microsoft Windows 64-bit platform, and bootkits in particular. Here is a self-explanatory diagram depicting the evolution of bootkit threats over time:
http://blog.eset.com/2012/01/03/bootkit-threat-evolution-in-2011-2
