VAC reads and sends your browser history
Posted: Sun Feb 16, 2014 5:43 pm
Quote from ROCK-KNIGHT on Reddit.
http://www.reddit.com/r/gaming/comments ... user_from/
http://www.reddit.com/r/gaming/comments ... user_from/
tl;dr when you connect to a VAC secured game server, all recent domain queries you have made (essentially what servers/websites you have connected to) are sent to a VAC server.
Courtesy of http://www.reddit.com/r/GlobalOffensive ... e_visited/
Decompiled module: http://i.imgur.com/z9dppCk.png What it does:
Goes through all your DNS Cache entries (ipconfig /displaydns)
Hashes each one with md5
Reports back to VAC Servers
So the domain reddit.com would be 1fd7de7da0fce4963f775a5fdb894db5 or organner.pl would be 107cad71e7442611aa633818de5f2930 (Although this might not be fully correct because it seems to be doing something to characters between A-Z, possible making them lowercase)
Hashing with md5 is not full proof, they can be reversed easily nowadays using rainbowtables. So they are relying on a weak hashing function
You dont have to visit the site, any query to the site (an image, a redirect link, a file on the server) will be added to the dns cache. And only the domain will be in your cache, no full urls. Entries in the cache remains till they expire or at most 1 day (might not be 100% accurate), but they dont last forever.
We don't know how long this information is kept on their servers, maybe forever, maybe a few days. It's probably done everytime you join a vac server. It seems they are moving from detecting the cheats themselves to computer forensics. Relying on leftover data from using the cheats. This has been done by other anticheats, like punkbuster and resulted in false bans. Although im not saying they will ban people from simply visiting the site, just that it can be easily exploited
Original thread removed, reposted as self text (eNzyy: Hey, please could you present the information in a self post rather than linking to a hacking site. Thanks)
EDIT1: To replicate this yourself, you will have to dump the vac modules from the game. Vac modules are streamed from vac servers and attach themselves to either steamservice.exe or steam.exe (not sure which one). Once you dump it, you can load the dll into ida and decompile it yourself, then reverse it to find the winapi calls it is using and come to the conclusion yourself. There might be software/code out there to dump vac modules. But its not an easy task. And on a final note, you shouldn't trust anyone with your data, even if its valve. At the very least they should have a clear privacy policy for vac.
End of copy/paste from /r/globaloffensive
...I expect this post wont go anywhere, though. The Valve defense force will show up any minute now... Just imagine that EA did this.