If you are using a pop-up blocker, then it's doing its job.

wow. thank you! I felt stupid when i read this...b/c yes pop up blocker. Thank you! So, i started paying attention to them. I have noticed that they also come up while i am not online.

This is defiantly something new within the past 3-4 weeks. Should i be concerned?

If you are saying the browser opens on its own,

You may have ad/mal-ware. Further information can be found in this article; https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

What i see are a flash of an invisible square come in center of monitor & disappear, the browser does not open.

I will look at the link and see what i can do; just in case it applies here.

If you are seeing those "popups" when Firefox isn't even running, I would say you need help from your anti-virus program support or help forum. Or maybe a site specializing in Malware detection and removal.

Ok. Thank you for your help!

Has your problem been solved?

If you haven't already, please select the answer that solves the problem. This will help other users with similar problems find the solution more easily.

Thank you for contacting Mozilla Support.

No i have not found solution. I was going to look into the option that maybe this is a windows 10 issue as it happens with no browser opened both laptop and desktop while working on drawing/designing/bidding programs.

thank you! will keep you updated.