Its probably a scam.. don't download it. It most likely replaces your login window with a fake one that steals your info.
Read the above post.. and go to your youtube link, I posted a comment.
Don't believe anything on youtube.. its all scam.
Hack as in cheat for a game or as in cafe launcher that actually let you play all the games on all the VAC2 servers?
I bet it was one of these:
Cracked steam
Outdated steam cafe launcher
Outdated key generator
Or something else outdated..
The security is much stronger, I don't think old programs would bypass it.
If you found a working hack.. why are you posting this..
The low quality video, first give away.
The public link, second give away.
Cafe stuff will never be public again!!!