Reports from a Russian website have spread today that the engine codebase for the Source 2007 engine has been leaked. The breach seems to have occured a long time ago but only now have the files surfaced which we have seen available for download in various locations.
According to those who have accessed the material, the files contain information for Team Fortress 2, Counter Strike: Source, Day of Defeat: Source, Half-life: Source, Portal, Portal - Multiplayer test (the failed original MP for Portal) and Half-life 2: Deathmatch. According to our researchers only one reference to Episode 3 exists, which resides in the code for npc_surface.
Interlopers states that the engine was packaged in this form for game developers who license the Source engine.
Valve have previously been asked whether they would make the source code available for any of their games, even those on the gldsrc engine but said they would not as it makes exploiting the engine easier for cheats in their multiplayer titles. As such we imagine this could turn out to be a problem for some of the titles mentioned above, although the code is somewhat outdated (2007) and as such, most games have long since been updated from this version.
More updates on this soon.