He said he does not know why the command-and-control servers were shut down.

他说，他不知道为什么指挥和控制服务器被关闭。

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These companies built software that spreads data across the globe, automated the command and control of tens of thousands of servers, and refined data-center designs to be more energy-efficient.

这些公司构建可在全球分布数据、自动执行命令和控制数万服务器的软件，完善数据中心的设计使之更具能效。

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Damballa discovered the botnet in March and has been tracking its communication with command-and-control servers around the world.

FORBES: Chinese Botnet Sells Point-And-Click Cyberattacks

Internet security firm FireEye has spotted some 450, 000 infected computers from the Srizbi botnet - alleged to account for as much as half of all the spam on Earth - trying to "phone home" and reach their command and control servers.

BBC: Spam on rise after brief reprieve