Half-Life 2 Source Leak Update
1) We've taken our network connection down to pretty much a minimum. We're still finding machines internally that have been compromised.
2) The suite of tools that the attacker was using included the modified version of RemotelyAnywhere (basically a Remote Desktop-style remote admin tool), Haxker Defender (a process, registry key and file hiding tool), the key logger, and various networking utilities that allowed them to transfer files (compressors, NetCat, and FTP). We also are pretty sure they were sniffing our network to gather passwords and other information. Haxker Defender includes a file system driver that allows an attacker to have stuff on your machine that is invisible, unless you do something like mount the drive under another OS that has NTFS support.
We have determined one way of detecting some infected machines, which is using a connection viewer to detect connections to anomalous hosts external to our network.
We still don't know their entry method.
3) In general, the community has been remarkably swift at tracking down the sources of the leak. What would be most helpful now are IP addresses of the people who were responsible for the intrusion or for the denial of service attacks.
4) Also, please continue to send in URLs of websites hosting the source code. We've been contacting people and asking them to take it down.
5) There's anecdotal evidence that other game developers have been targeted by whoever attacked us. This hasn't been confirmed. We've been providing other game developers with more detailed information about the exploits and evidence of infiltration.
6) We're running a little bit blind with our network shut down, but it seems like some of the press has picked up the story. I've been fielding calls from the mainstream non-games, non-technical press.all day. Hopefully they will get to report shortly what a mistake it is to piss off a whole bunch of gamers and get them hunting you around the Internet.
For any information related to this, please send it to helpvalve@valvesoftware.com, or you can always send to gaben@valvesoftware.com as well.