In 48 hours, number of Koobface C&C servers has grown from 71 to 142, doubling the total number. Trend is to increase the usage of servers hosted in the United States, making the top 10 of countries which host Koobfaces. KoobFace, for example, uses compromised legitimate websites as proxies for their main command and control server. The number of infected computers connected to infected computers in the U.S. is always oscillating, going from above to below 100 and back in a matter of weeks.
Source: https://threatpost.com/koobface-worm-doubles-cc-servers-48-hours-031110/73669/