The four, aged between 18 and 28, are alleged to have stolen Xbox technology, Apache helicopter training software and pre-release copies of games such as Call of Duty: Modern Warfare 3, according to an indictment dating from April that was unsealed on Tuesday.
Two of the hackers pleaded guilty earlier in the day, the DoJ said.
“These were extremely sophisticated hackers ... Don’t be fooled by their ages,” assistant US attorney Ed McAndrew said after a court hearing on Tuesday.
According to prosecutors, the defendants stole intellectual property and other proprietary data related to the Xbox One gaming console and Xbox Live online gaming system, and pre-release copies of popular video games. The Department of Justice (DoJ) claimed the technology was worth between $100m and $200m, a figure hotly disputed by one of those facing charges.
The four charged in the US were named as Nathan Leroux, 20, of Bowie, Maryland; Sanadodeh Nesheiwat, 28, of Washington, New Jersey; David Pokora, 22, of Mississauga, Ontario, Canada; and Austin Alcala, 18, of McCordsville, Indiana. The DoJ also said a man faces charges in Australia in connection with the same allegations. It did not name him in the announcement, but he was identified by Australian media earlier this year as Dylan Wheeler, 19, from Perth.
Pokora and Nesheiwat each pleaded guilty to a single count of conspiracy to commit computer fraud and copyright infringement. They face up to five years in prison when sentenced in January.
The four in the US had been jointly charged with with conspiracies to commit computer fraud, copyright infringement, wire fraud, mail fraud, identity theft and theft of trade secrets. They were also individually charged with individual counts of aggravated identity theft, unauthorised computer access, copyright infringement and wire fraud. The charges were based on a federal grand jury indictment returned in April.
The hackers are alleged to have accessed the computer system of Zombie Studios, which allowed them to access a Apache helicopter training simulation program that the company had developed for the US army.
Other targets of the alleged hacks included Microsoft, and game companies Epic Games and Valve, the DoJ announced. It said the US has seized $620,000 in proceeds “related to the charged conduct”.
“As the indictment charges, the members of this international hacking ring stole trade secret data used in high-tech American products, ranging from software that trains US soldiers to fly Apache helicopters to Xbox games that entertain millions around the world,” said assistant US attorney General Caldwell.
McAndrew said FBI officials in Delaware were alerted to the hacking operation in January 2011 by a confidential informant, and that the gaming companies cooperated in the investigation.
Authorities began obtaining arrest warrants last year, and Pokora, who McAndrew said was looked to by other group members as a leader, was taken into custody in March at a border crossing in Lewiston, New York.
A copy of part of the sealed indictment, obtained by thesmokinggun.com in April, detailed the charges against three of the four alleged hackers: Leroux, Nesheiwat and Pokora. Alcala was not mentioned in the leaked document.
Pokora’s plea is believed to be the first conviction of a foreign-based individual for hacking into US businesses to steal trade secret information, authorities said.
The DoJ also said that “an Australian citizen has been charged under Australian law for his alleged role in the conspiracy”. It did not name Wheeler, who attracted attention in 2012 when he listed a home-made development prototype of the Xbox One, which at the time was still in development by Microsoft, on eBay. He was 17 at the time.
Wheeler is currently on bail awaiting trial for charges relating to these allegations. which he denies. He told the Guardian that he disputes the DoJ’s estimated value of the alleged thefts - $100m to $200m - as “meaningless”. He also said that the $620,000 seized was from an act of theft by a single hacker in an “extremely disorganised group.”
“Apart from that, the group made nothing,” he said. “It was just curiosity.”