Steam2 Teraleak: 12 TB of Valve's internal archives out in the wild, no hacking involved

Fabian Lainé August 30, 2026 at 7:00 AM

In brief

12 TB of internal Valve archives, dating from 2003 to 2013, have been circulating since late August under the name Steam2 Teraleak. No hacking was involved: a researcher confirmed that the content came from public access to outdated infrastructure that had been left open. The leak reportedly contains early versions of Portal 2, Left 4 Dead, CS:GO, and the cancelled F-Stop project.

An archive of roughly 12 TB of internal Valve content has been circulating since late August under the name "Steam2 Teraleak". It reportedly comes from the publisher's old content servers, the ones using the GCF format, predating SteamPipe.

What the archive is said to contain

Researcher Gabe Follower, who has been tracking Valve for years, documented it on the evening of August 29: someone allegedly leaked 12 TB of internal builds and development assets covering 2003 to 2013, including early versions of Portal 2, Left 4 Dead, CS:GO, and the cancelled F-Stop project.

He adds "and potentially EP3", meaning Half-Life 2: Episode Three. Nothing has been confirmed: the community is still digging through the trove, and initial technical analysis points to F-Stop assets with no playable level whatsoever, and nothing resembling Episode Three.

An Aperture Science test chamber in Portal 2, with an orange portal on a panel and a blue stream crossing the room above two turrets. — Portal 2 is one of the games whose development builds are said to appear in the archive. Credit: Valve

Reliability: this isn't a hack

This is the point that most coverage buries. A few hours later, Gabe Follower clarified that no hacking was involved: he says he verified that all of the Steam2 Teraleak content was obtained through a publicly accessible endpoint, and concludes: "It's Valve's fault". A door left open on outdated infrastructure, not an intrusion.

Valve has said nothing publicly. As long as the company stays silent and the sorting of the trove remains unfinished, anything touching on Episode 3 belongs to wishful thinking, not discovery.

Do you think Valve should be transparent about this leak and its consequences?

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Frequently asked questions

How did this leak happen?

A public access point to old Valve content servers (GCF format, predating SteamPipe) left 12 TB of data accessible without authentication. No hacking was necessary: it was simply a door left open by Valve.

Is Half-Life 2: Episode Three really in the leak?

Not confirmed for now. While Gabe Follower mentioned it as potentially present, initial technical analysis found no trace of a playable Episode Three. The community is still digging, but nothing concrete has been established.

What content has actually been found?

Documented development versions of Portal 2, Left 4 Dead, CS:GO, and resources from the cancelled F-Stop project. The rest of the 12 TB is still being explored by the community.

Has Valve responded?

No, the company has made no public statement so far about this leak of internal archives.

Key takeaways

12 TB of internal Valve builds and development resources from between 2003 and 2013 are in public circulation
This isn't a hack but a security flaw: unsecured access to legacy GCF servers, left open by Valve
The archives reportedly contain development versions of Portal 2, Left 4 Dead, and CS:GO, but nothing proven about Half-Life 2: Episode Three
The community is still combing through the data, and Valve has made no public statement about the incident

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