Just a word for the wise: it's called "phishing", not "hacking".
But yeah, Valve has a few issues with phishing on Steam. The problem is,
there are legit links -
http://steampowered.com/nvidia/ and
http://steampowered.com/ati_offer1a/ are both legitimate, linked to by a sticky
http://forums.steampowered.com/forums/showthread.php?t=851573 here in the Steam main forums (
http://forums.steampowered.com/forums/forumdisplay.php?f=14). I've added the link trail to prove that
I'm not phishing, possibly a fear when some random dude starts posting links in a thread about a phishing scam.
Problem is, since basically everybody has used official Steam websites for free stuff, it's a lot more likely that people will use
phishing websites hoping for free stuff.
Oh, and since I don't see it linked here yet, the official Steam Support article for reclaiming accounts is
https://support.steampowered.com/kb_article.php?s=97b04246c77b19f644cf77ffc399e721&ref=2347-QDFN-4366. Even if you don't have your e-mail, it's
possible you'll be able to provide proof-of-purchase information and get your account back, both for retail and digital purchases.
Just a friendly reminder:
report it quickly - apparently, hijacked accounts are quickly resold (at a fraction of the cost of the games on said account), and there's a decent chance the new owner will start using hacks. If your account is VAC-banned,
there is absolutely nothing Steam can do. Even if your account is reclaimed, it'll be VAC-banned, because apparently it's an irreversible state. You'll be unable to ever play online again, unless you create a new account and re-purchase any online games.