A 20-year-old Californian has been charged by federal investigators for building and managing a botnet of PCs numbering around 400,000 machines, some owned by the US Department of Defense.
The man has been accused of renting out the bots to others or using them himself to gain money by distributing adware on behalf of marketing companies.
Bots or “zombies” are computers remotely controlled by hackers without their owners knowing they are infected with programs that allow them to be controlled by third parties, for malicious or monetary gain.
It is believed to be the first case in the US where the FBI has charged someone accused of running a botnet.
The man has been charged on various counts, including conspiracy, damaging federal government computers and illegally accessing PCs to commit money-laundering and fraud.
The man is said to have used a customised version of the “rxbot” bot worm program to infect as many as 400,000 computers to create his botnet of machines.
Three people in the Netherlands were recently charged for building a botnet much larger than the one generated from California.