Help!! I'm afraid my forum is somehow "infected" with something!

[Lea Verou]

I just received the followning message:

Dear user michelle,

You have successfully updated the password of your E-steki account.

If you did not authorize this change or if you need assistance with your account, please contact E-steki customer service at: webmaster@e-steki.com

Thank you for using E-steki!
The E-steki Support Team

from webmaster@e-steki.com. It had an infected attachment as well (avast stopped it before I got to the message). Also, we don't have such an account (webmaster@e-steki.com) and we don't sell anything so we don't have "customers"! I opened a thread in my forum to ask if other members got the same message but none answered so far.
Any ideas of what might have happened???