Can you add a screenshot => More info here How do I create a screenshot of my problem?.

And check for malware with all the programs provided below.

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• TDSSKiller - AntiRootkit Utility
• Hitman Pro
• ESET Online Scanner

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Ran Norton Internet Security but virus remains.

See attached png screenshot

Did you use any of the tools i provided above? or safe mode as cor-el stated? it looks to be a malicious addon or some type of malware.

Waka_Flocka_Flame:

I ran the Quickscan option of Microsoft Safety Scanner; it could not find any virus or malware. But something is clearly there. I am going to try cor-el's suggestion.

I found a reference on the internet staing that pinterest.aot.im is a "browser hijacker".

rxbb

Starting Firefox in Safe Mode, as cor-el suggested, prevented the pinterest.aot.im popup window from activating.

But from now on do I always have to start Firefox in safe mode?

I would still like to get rid of this intrusion.

If it works in Safe Mode and in normal mode with all extensions (Firefox/Tools > Add-ons > Extensions) disabled then try to find which extension is causing it by enabling one extension at a time until the problem reappears.

Close and restart Firefox after each change via "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: Firefox > Quit Firefox; Linux: Firefox/File > Quit)

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

• If you have many extensions then first enable half of the extensions to test which half has the problem.
• Continue to divide the bad half that still has the issue until you find which one is causing it.