Steam suffers huge 12TB leak affecting hundreds of games, including Half-Life 3 content

Valve has experienced a huge data breach, with 12TB of files archived between 2003 and 2013 being leaked onto the internet.

The content of these leaks doesn’t appear to be user data or any private information of Steam users, but rather assets and code related to games that have been published on the platform itself.

The leaked material appears to have been accessed by a legacy endpoint that was available publicly, rather than a new hack.

What content has been affected by the 12TB Valve leak?

Early material for games like Portal 2, Left 4 Dead, and Counter-Strike: Global Offensive have been leaked, giving us a glimpse at what some early builds for these games looked like.

In addition to this, the leak has also affected various developers and publishers who launched games on Steam during 2003 and 2013, potentially affecting hundreds of different titles.

Although only a small part of the leaks have been revealed so far, X user Gabe Follower has reported on some of the more noteworthy bits of information that have come to light as a result, with YouTuber snoopdoggfan4173 explaining them in more detail.

It appears that so far, the biggest hits came to Portal 2 and Left 4 Dead, which released in 2011 and 2008 respectively.

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Portal 2

The Portal 2 leaks include a build from 2009 which features a test card instead of the end credits. There’s also a pre-rendered intro video featuring the player falling down one of the pipes within the Aperture lab.

This build of the game is old enough that some scenes are still incredibly unfinished, with the player character using the TF2 soldier arms as a placeholder.

These leaks also link to a project called F-Stop, an experimental prototype Valve created in which the player character uses a camera which can photograph an object, store it, and then place it somewhere else, sometimes at a different size.

The Portal 2 leak also features some unused early models and animations for various props that would appear in the final game, such as an animation test model for GLaDOS and animations for a zombie enemy that was originally going to feature in the game.

Half-Life 2: Episode 3

Interestingly, the leaks also feature a model for something called the Weaponizer, which has been linked to a weapon concept originally conceived for Half Life 2: Episode Three, which was later cancelled by Valve. It appears to have been reused as a placeholder for material appearing in Portal 2.

Left 4 Dead

Meanwhile, Left 4 Dead’s leaks include a fully playable early beta build dated June 2008, with functionality for co-op and versus modes.

This build features several differences, including an early beta HUD, changes to level geometry, a work-in-progress lobby screen. It also has some animations and audio that were cut from the final game, including lines that were originally recorded for Zoey by Alésia Glidewell before she was replaced by Jen Taylor.

Some assets from 2005 when Left 4 Dead was a mod for Counter-Strike: Condition Zero called “Terror Strike” have also been featured in the leaks, offering an early look at some of the game’s maps before it became its own fully fledged game.

That's all we know for now, but in the coming days, there will likely be more leaked material that will hit the internet.