From earlier today. For those of you who don’t already know, the steam forums security was compromised.
IF you have an account and your login information is the same as your steam account itself, start taking security measures. Even then plug in steam guard and the like.
Soruce(s):
https://www.pcgamer.com/2011/11/07/steam-forums-down-after-possible-hacker-attack/
https://www.gamepolitics.com/2011/11/07/report-steam-forums-down-possibly-hacked
https://www.gamefront.com/steam-forums-down-after-hackers-reportedly-hijack-them/
Discuss.
Edit: Thread name changed since it was a deeper hack than expected.
New Source: https://www.bbc.co.uk/news/technology-15690187