Microsoft released its Security Intelligence Report on October 13th, part of which tracks the spread of botnets in various countries based on the detection and cleaning of machines by Microsoft. According to that report, there were more than 2 million such systems detected and cleaned during each of the first two quarters of 2010. That means more than 5 out of every 1000 computers were infected. Although total numbers were lower for other countries, the percentage of computers infected was higher for Spain, Korea, and Mexico. The total number of botnet infections found and removed was twice the number for the same period in 2009.
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