Cyber-ring targets 2.3m computers
The FBI and the Justice Department has started to dismantle a ring of international computer thieves in the biggest enforcement action in the US against cyber-criminals.
The criminals have stolen an undetermined amount of money by infecting more than 2.3 million drives with malicious software.
On Wednesday night investigators were trying to contain a malware program called Coreflood by obtaining search warrants for computer servers around the country and by executing a court order to seize 29 domain names.
The malware exploits a vulnerability in computers running Windows operating systems and allows those that are infected to be controlled remotely.
Thirteen defendants, identified only as John Does, were accused in a civil complaint of engaging in wire fraud, bank fraud and illegal interception of electronic communications.
Some 1.8 million of the infected computers are in the US, the remainder around the world.
The US attorney for Connecticut, David Fein, said the government would be seizing servers and internet domain names that have the Coreflood malware.
In addition, a court order authorised the government to respond to signals sent from infected computers in the US, a move designed to stop the Coreflood software from running. The purpose is to prevent further harm to hundreds of thousands of unsuspecting users of infected computers.
The thieves engaged in wire transfers from the infected computers to steal 115,000 dollars (£71,000) from a Michigan property company; 78,000 dollars (£48,000) from a legal firm in South Carolina; 151,000 dollars (£93,200) from an investment company in North Carolina; and 241,000 dollars (£25,300) from a defence contractor in Tennessee.
The extent of the financial loss caused by the Coreflood botnet - the word "botnet" is derived from "robot" - is not known because of the large number of computers infected and the quantity of data stolen.