Thirteen terabytes of data leak through a publicly accessible endpoint

A publicly accessible endpoint in Valve’s old infrastructure has released an enormous archive of game data, revealing roughly a decade of development work without a conventional break-in or security breach. Archivists extracted between 12 and 13 terabytes from Steam, covering material uploaded between 2003 and 2013.

The archive stretches beyond Valve’s own projects. It reportedly contains early versions of third-party titles including Call of Duty, Resident Evil, Mirror’s Edge, Batman: Arkham Asylum and Dragon Age: Origins. The files are still being examined, but the scale of the leak has already exposed a broad record of how games changed before release.

Some of the most closely watched discoveries concern unfinished Portal 2 content and Half-Life 2: Episode 3. Researchers found deleted dialogue, alternative opening sequences and a tool called “weaponizer”, designed for Half-Life 2: Episode 3. The tool could reportedly turn objects into ammunition, but the game never received a final release after development was officially halted in 2024. A modified form of the idea later appeared as a paint or gel shooter in a Portal 2 mod.

Portal 2’s archive also contains unused sequences, beta menus and altered opening scenes. A July 2009 beta version featured a substantially different GLaDOS interface character, with a more passive role and different voice lines. Early versions of Left 4 Dead and Counter-Strike: Global Offensive were also found, offering glimpses of different stages in the development of those games.

The material has attracted attention because it preserves discarded ideas as well as unfinished builds. Rather than revealing a single completed product, the archive shows the many changes that took place before several well-known games reached their final forms.