It looks at least two members of WoC got their account hacked, VenDetta and our new recruit Emre. Their hacked Steam accounts sent spam messages to everyone in their friends list who was online by that time.
Therefore I'd like every member to note that YOU MUST NOT CLICK AT ANY LINKS THAT PEOPLE WRITE YOU ON STEAM, NO MATTER WHETHER HE IS A KNOWN FRIEND OF YOU OR NOT!! And even more important, if you clicked at such a link, do NOT log-in with your Steam log-in at the website that will open.
VenDetta, did you have any luck with the Steam support yet? If so, could you tell us what you've done so far, in order to get your account back? Hopefully your experience can help other members (Emre/fiyancetto) to get their accounts back faster.
As Dneed has said. There are some very convincing hijack sites that look exactly like the Steam login page. It may have offered you free games or just a link to a game update etc.
When you enter your login and pass it goes directly to the sites owner and he then has access to your account and games.
Just be sure to keep an eye on the website address at the top bar, thats the best place to spot it.