Credit: Valve
Data miners Gabe Follower and Scolcer discovered 12 TB of internal Steam archives from 2003 to 2013 on an open Valve server. The leaked data includes early builds of Portal 2, CS:GO, Left 4 Dead, and materials from the canceled F-Stop project.
The leak turned out to be the result not of a hack, but of a Valve error. The archive was discovered on a public access point connected to Steam2, an outdated system for delivering and storing game content.
Valve used Steam2 from 2003 to 2013, so the leak is limited to that period. The archive includes a wealth of game assets and internal builds, including early versions of Portal 2, Left 4 Dead, CS:GO, and F-Stop (the Portal prequel).
The community also expects to find information about Half-Life 2: Episode Three, the mythical sequel to Half-Life 2: Episode Two, a prototype of which was being developed during that period.
Valve has not commented on the incident. A preliminary list of all discovered file storage locations is already available on GitHub, but researchers warn that fully cataloging the 12 TB will take considerable time. It is unknown whether the company managed to close the unsecured address before the data was leaked.