This is going to sound strange, but... Your More System Details lists an add-on named "SearchDonkey". Try disabling that to see whether it stops these unwanted pages.

Open the Add-ons page using either:

• Ctrl+Shift+a
• orange Firefox button (or Tools menu) > Add-ons

In the left column, click Extensions.

Can you disable or remove it?

You may also need to visit the Windows Control Panel, Uninstall a Program, to fully flush it out. Try clicking the "Installed on" column heading to bring the most recent infections (I mean, additions) to the top. Grouping by date can help uncover bundle items that you didn't realize you were installing. Remove as much junk as you can.

Finally, this support article lists some other tools you can use for supplemental scanning and cleaning: Troubleshoot Firefox issues caused by malware.

Any luck?

Edit: P.S. Arcade Parlor also could be a problem; try to get rid of that one as well.

You may also want to look into K9 to proactively block sites you haven't approved for your children.

http://www1.k9webprotection.com/

Go to the Mozilla Add-ons Web Page (There’s a lot of good stuff here) and check out BlockSite.

BlockSite is an extension, which automagically blocks websites of your choice. Additionally, this extension will disable all hyperlinks to these websites, by just displaying the link text without the clicking functionality.

kk thank you ever so much

Well I looked at BlockSite and it seems it has been failing Miserably, I won't chance that. I did remove that search donkey. Didn't know it was there and really wondered why things were highlighted. What I need is something that will allow me to simply put a webpage address into a list and that webpage will not appear anymore. I looked at EVERY single one of the programs/addons in that blocksite category and they have a million ad blocks,Facebook, gif's etc. also content blocks. Those I don't need, all my children are grown and use their phones not my computer. Just a program that will allow me to put an address into it and that address can't be, will never be accessed or allowed to be accessed again. I know ther are those of you out there smart enough to make this for Mozilla so PLEASE do so. You will make me and many others very happy. Thank you Ed

What makes you believe it is a malware site?

Hi EdtheAminal, this extension doesn't block a page, but allows you to redirect the address to a different one, which could be a preferred page or perhaps a blank page. It sounds easy to use (right-click unwanted page to create the redirect). Maybe worth a try? https://addons.mozilla.org/firefox/addon/redirector/