The attackers claimed to have downloaded source code for games such as FIFA 21 and for the proprietary Frostbite game engine used as the base for many other high-profile games.
The firm is one of the largest games companies in the world. It counts major series such as Battlefield, Star Wars: Jedi Fallen Order, The Sims, and Titanfall among the titles it develops or publishes - as well as a vast array of annual sports games.
"We are investigating a recent incident of intrusion into our network where a limited amount of game source code and related tools were stolen," an EA spokesperson said in a statement.
The company said it had already improved security and stated that it did not expect "an impact on our games or our business".
In its report, Vice said it had seen screenshots of the hacking forums used by the attackers, who are advertising the stolen data for sale.