The U.S. Justice Department and the FBI were granted unprecedented authority this week to seize control over a criminal botnet that enslaved millions of computers. Coreflood has morphed into a menacing crime machine since its emergence in 2002. The government was able to have the botnet control servers redirected to networks run by the nonprofit Internet Systems Consortium (ISC)2 When bots reported to the control servers as they were programmed to do periodically the ISC servers would reply with commands telling the bot program to quit.”]
Source: https://krebsonsecurity.com/2011/04/u-s-government-takes-down-coreflood-botnet/