True, I got the same chat message. Unfortunately I clicked on the link and tried to log in but as it did not work (thanks to 2-factor-auth via Steam app) I changed my Steam account password immediately.
I also took a closer look at the website. It is a fake and just wants you to log in with your Steam account. Probably to hijack your account.

Might have been taken over by a bot (temporarily?). In case you receive a chat message asking you to "vote for [their] team at fastleague", DO NOT LOG IN ON THAT WEBSITE .