Four members of an international computer hacking ring were charged with breaking into the networks of the U.S. Army and several technology companies in an indictment unsealed on Sept.30. In addition to stealing software and data related to video game systems, the indictment charges the defendants stole proprietary software used to train Apache helicopter pilots.

The alleged cyber-theft included Apache helicopter simulator software developed by Zombie Studios for the U.S. Army.

Assistant Attorney General Leslie Caldwell of the Justice Department’s Criminal Division noted “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 U.S. soldiers to fly Apache helicopters to Xbox games that entertain millions around the world.”

The defendants and others allegedly gained access to computer networks through stolen usernames and passwords of company employees and software development partners and SQL injection. After entering the computer networks, the perpetrators accessed and stole trade secrets, software source code, copyrighted works, and other confidential information. The stolen data and intellectual property is estimated to be worth $100-$200 million.