Go to the Mozilla Add-ons Web Page {web Link} (There’s a lot of good stuff here) and search for a good ad / pop-up blocker.

Hello DaisyKay,

Your system details show that this add-on is installed :

MapsScout 165.6385.1559.33

It's malware, that inundates you with all kinds of ads (and more).

Go to Preferences => Add-ons => Extensions, and remove the culprit.

It might also be wise to run the malware scans that are listed in this article :

https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

Also see : https://productforums.google.com/forum/#!topic/maps/9voKzYMywNk

Thank you. I removed it. I have no idea how it got there.

It’s very sad, but many software downloaders/ installers will trick you into installing not only their program, but other programs as well.

You have heard of the fine print in shady contracts, right? Well, some installers you need to look at the itsy bitsy teeny weeny fine print.

You are thinking you are giving the installer permission to install the program you want by using the recommended option. But if you use the Manual Option Instead, you discover all kinds of stuff that you do not even know what it is or what it does.

From now on, everyone needs to Use The Manual Option to put a stop to this.

Note that these programs can also change browser/computer settings.

Also please read this :

http://www.spywaretechs.com/remove-maps-scout-extension/

It might be a good idea to regularly check Preferences => Add-ons => Extensions, to see if there is anything there that you didn't install yourself - and if you find any : remove it right away.