am i being hacked? advice please
 

hi-

i'm hoping someone here has an answer to this.

on some of my more popular sites i'm checking the referral logs and see lots of hits from URLs like this:

http://www.lesbomat.com/usrs/login.php
http://dual.ix.nu/ChatMessagesPage.php
http://members.aysum.com/
http://www.ddfcup.com/usrs/login.php

when i go to these URLs they are templates that require a member name/pass.

now, there isn't that much to see in my visitor's section, and we have scripts on the server that protect against brute force attacks and multiple users with the same name/password...

so what gives with this?

yes, i can block the domains, but does anyone know what's really happening with this?

thanks!