I get malware t4.liverail.com pop ups in FF only.
At some point over the last few days I started getting seemingly random pop ups of the standard windows ID/PW input box (the type you get when you go into a folder on a web site that is controlled by an .htaccess file). It asks me to enter my ID and password and say it is from t4.liverail.com going on to state that the info will NOT be sent to the web site I am currently viewing. I have scanned with a fully up to date AV software and several malware apps and none have found anything. WTF is causing this and how do I get rid of it?