In a detailed article, PC World's Erik Larkin describes how a team of security researchers managed to bring down a 250,000-pronged botnet.

"For two years as a researcher with security company FireEye, Atif Mushtaq worked to keep Mega-D bot malware from infecting clients' networks," Larkin writes. "In the process, he learned how its controllers operated it."

"In November, he suddenly switched from defense to offense," Larkin adds. "And Mega-D -- a powerful, resilient botnet that had forced 250,000 PCs to do its bidding -- went down."

Click here to read the PC World story.