A massive leak of more than 12 terabytes of Steam game data spanning from 2003 to 2013 emerged online on August 28 or 29, exposing early and beta versions of several Valve games as well as assets from canceled projects [1, 2, 3, 4].
The archive contains internal builds of Portal 2, Left 4 Dead, Left 4 Dead 2, Counter-Strike: Global Offensive, and the canceled Portal prequel F-Stop [1, 5, 6, 7, 3, 4, 8, 9]. It also includes assets linked to the canceled Half-Life 2: Episode 3, such as a model of the Weaponizer weapon associated with the project, although no playable builds of Half-Life 3 or Episode 3 have surfaced so far [1, 5, 7, 3, 8, 9].
The leak extends beyond Valve titles, with files from third-party games like Call of Duty, Resident Evil, Dragon Age: Origins, Batman: Arkham Asylum, Mafia 2, and Grand Theft Auto 3 also present in the data [5, 10, 9].
Security researchers tracing the source found that the data came from Valve's old Steam2 content delivery system, which operated before Valve switched to the SteamPipe platform in 2013 [1, 11, 6, 7, 2, 4, 12, 9]. The leak was obtained through an unprotected API endpoint on the Steam2 servers rather than hacking, a Valve content creator said, adding "It’s Valve’s fault" for the exposure [1, 11, 6, 4, 9].
Community members have started mining the files, with several videos and mods recreating the Portal 2 2009 beta build appearing online [1, 7, 4]. Gabe Follower, a Valve content creator, said the community was still researching the contents and anticipated "the next few days might be insane" [1]. Ex-Valve developer Elan Ruskin quipped about early versions, advising against wasting time on prerelease builds, noting that all good ideas ended up in final releases [2].
Valve has not issued a public statement about the leak as of now [1, 6, 9].
The 12-13TB data set covers Steam content from 2003 until the 2013 transition to SteamPipe, explaining the cutoff of the archive's timeline [1, 11, 6, 4, 12, 9].
Further analysis by the community is ongoing as researchers continue to explore the breadth of the leaked files.
