For two years as a researcher with security company FireEye, Atif Mushtaq
worked to keep Mega-D bot malware from infecting clients' networks. In the
process, he learned how its controllers operated it. Last June, he began
publishing his findings online. In November, he suddenly switched from
defense to offense. And Mega-D--a powerful, resilient botnet that had forced
250,000 PCs to do its bidding--went down.
