According to Vitaly Kamluk of Kaspersky Lab, more than 20 million computers are infected by the four leading botnets.

"The largest botnet is Conficker, with more than 8 million infected hosts, followed by TDSS with more than 5.5 million, Zeus with more than 3.6 million, and Koobface with more than 2.9 million, according to Kamluk, chief malware expert for Kaspersky Lab’s Global Research and Analysis Team," Infosecurity reports.

"He told a web conference today that there are currently more than 53,000 botnet command-and-control servers on the Internet," the article states.

Go to "Major botnets have infected over 20 million computers, says Kaspersky" to read the details.

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