I also am receiving an Infection Detected. And it pops up whenever I go to a new URL, or sometimes multiple times while I’m just reading your forum. It says:
Infection: JS:lframe-DHY [Trj]
URL: http://gntcdn.com/js_f.php?
{long and irrelevant, since I am not and as far as I can determine never have been to gntcdn.com}
File: {gzip}

Having many of these blocking screen real estate is a problem. Having them come back almost as fast as I can eliminate them is a pain.

Can you help me get rid of them?

I’m using Firefox 28.0 on a Powerbook Pro running OSX 10.7.5.

Thanks for any help you can give me.

Hamhanded