A major problem with Valve’s Steam games servers has apparently resulted in those servers being shut down today, Christmas Day.
It is not clear whether this was the result of an intrusion, but users, including security researcher HD Moore, noticed that, when logged in to one account, they could view details of other users’ accounts. This occurred despite two-factor authentication or the use of robust passwords. It has been suggested that this may be the result of a caching bug, but that remains speculative at present. Valve Corporation has therefore shut its Steam servers down for the time being.
If this is the result of an attack, then trying to connect to any Steam service or link could potentially take you into the arms of the attacker: you should therefore avoid trying to connect to any Steam or Steam-related page until the situation is clearer.
If you have an account on Steam’s servers, when they are up and running again, you should check that your account is in good order, and change your password as soon as possible. It appears that many passwords have been compromised.
No doubt Valve Corporation will provide full details shortly…