Mystereous Window Pops Up

On several websites I have a window pop up labeled "Connect To
afe.specificclick.net".It is a password window waiting for me to fill my
user ID and password.

I have searched the web and cannot find specific info or a way to clean this
window.It also appears to slow the loading of web pages.

I use Win XP Pro,IE7 and have run the whole series of malware and spyware
removers.I have modified my host file.

Is this a real threat?Any ideas/help?

TIA,
Bob


.