Does avast give you a specific detection that someone could research?

Add-ons can inject changes into pages, so perhaps avast dislikes one of your add-ons. A standard diagnostic to bypass interference by extensions (and some custom settings) is to try Firefox's Safe Mode.

First, I recommend backing up your Firefox settings in case something goes wrong. See Back up and restore information in Firefox profiles. (You can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.)

Next, restart Firefox in Firefox's Safe Mode (Diagnose Firefox issues using Troubleshoot Mode) using

Help > Restart with Add-ons Disabled

In the dialog, click "Start in Safe Mode."

If you can browse without messages, this points to one of your extensions or custom settings as the problem.

If you still get the messages, to further disable add-ons, you can try here:

orange Firefox button or classic Tools menu > Add-ons > Plugins category

Any change?

No Avast didn't give me a specific detection until I finished the entire scan on system. I was good until I put the Add-On "Do Not Track Plus" on there and after that is when my troubles started because that and updating to ff 15 was the only changes I did and ff 15 isn't gonna give me what I got. I ended up with JJ:blacole:BV ?? when I researched it, it was a trojan, spelling might be off - it was late last night and I didn't write it down. I wasn't on any other sites to get this so it had to be the add on for me to get it, I am very cautious on where I go b/c of worrying about virus'.

Thank you very much for your input and help. Have a good day.