blocking dns server

hi everybody!

i have a strange trouble in a windows 2000 dns server that has avast server installed (with licence)
this server is sending many requests for those websites : www.superbetcs.com & www.vote2fateh.com … (thanks to ethereal.)
i found that there is varients of Trojan.Tooso (L, M, …) , virus Bagle, Win32.Glieder and others that put files, modify the registry and try to download files from those websites.
i tried to remove this worm manually but i havent found anything. even the scan with avast has found nothing. but there’s still thousands dns requests for www.superbetcs.com & www.vote2fateh.com.

somebody help meee plzzz!!!

I’m not an expert on servers… but can’t you run antispyware scannings in it?
Also, which firewall protect this server?
Does cleaning the DNS cache help?