Fake Clans / Fake Clan Sites Attempting to Obtain Steam Account Information
Method
VALVe has verified reports that people are setting up fake clans and/or fake clan websites with the express purpose of stealing Steam Accounts.
1) A "member" of a fake clan will offer membership, server Admin, or web site privileges in exchange for a Steam Account name and User password.
2) Registration information from a fake clan site is used in a brute force attack on a Steam Account.
Response
Under no circumstances should a legitimate site be asking for the password to your Steam Account.
DO NOT USE THE SAME PASSWORD FOR YOUR LOGIN TO ANY STEAM RELATED SITE AS YOU USE FOR YOUR STEAM ACCOUNT PASSWORD.
Action
If you come across a site that is asking for your Steam Account User password, please report it to a forum moderator immediately.
If you have provided your Steam Account name and User password to
any clan or web site you should immediately try to change your password to something else.
If this fails you will need to read the following FAQs:
Reclaiming a Hijacked Steam Account
Contacting VALVe Billing and Support
Account Security Recommendations