with this code you can see exactly how everything in the game starcraft works
basically once code is compiled its near impossible to reverse engineer
so you could mod it,or use the code to make your own game,etc
or the dude could have sold it on the black market
its not hard to be anonymous on the internet, free wifi is everywhere if he wanted to upload it without any chance of it tracing back to him
assuming he didn't talk about it first ofc
Except he already blurted out he found it. Had he stayed quiet, no one would have known or been able to link it. Just install a virtual machine on your computer, fake the MAC address, connect at a Starbucks, dump it on PasteBin and walk away.
Other things you could do with this:
Circumvent cheat protection
Deeply understand AI, pathing, build speeds, weakensses.
Find exploits and bugs to things no one would know otherwise
Run a special build online that can run your own maps that are hacked to give you special undetectable privilege
Connect to Battle.net and wreak havoc there
Find ways to spoof accounts, log in as someone else, and well...
Examine all the code and libraries used to see if maybe something was used improperly, without a license, which could get Blizzard in mega-trouble
It could also contain working logins, passwords and encryption keys for more than just Starcraft. Personal info of people, too. It was a self-made disc, most likely.
And considering games always build off the previous work, this could likely affect other games like Warcraft II or III.