Uh, if it is this one: http://securityresponse.symantec.com/avcenter/venc/data/backdoor.nettrojan.html
read the description carefully. Removing is a bit tricky for this one.

You can get some more infos here:
http://www.virusbtn.com/resources/vgrep/vgrep.cgi?terms=BackDoor-ANF&product=0