When I look for past threads, I see this is associated with a theme engine that may be called Personas Interactive and may fail to clean up after itself when you remove it. Let me link to those first, and in case those don't help, I'll add a post with more general suggestions:

• How can I stop the 'BrandThunder.com page opening when I open a new tab?
• How can I remove Brand Thunder?
• Okay so I have the latest version of firefox and today when I opened up a new tab I was brought to this search function by WebSearch+.

There are two ways a page can take over the "new tab" page:

(1) Changing the new tab page setting in Firefox (e.g., by creating a user.js file that overrides your preference every time you start Firefox);

(2) Using an extension to override your new tab page setting.

Let's check those:

Clean up Extensions

Disable ALL nonessential or unrecognized extensions on the following page. If in doubt, disable:

orange Firefox button (or Tools menu) > Add-ons > Extensions category

If a link appears above a disabled extension to restart Firefox, you can do that as the last step after completing your review of the list.

Update New Tab Setting

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box above the list, type or paste newtab and pause while the list is filtered

(3) Double-click the browser.newtab.url preference and enter your preferred page:

• (i) Page thumbnails (default) => about:newtab
• (ii) Blank tab => about:blank
• (iii) Built-in Firefox home page => about:home
• (iv) Any other page => full URL to the page

Press Ctrl+t to open a new tab and verify that it worked. Fixed?

Check for and remove a user.js file

To prevent your change from being reverted the next time you start Firefox, check for this files in your Firefox settings folder (also known as your Firefox profile folder). This article describes how: How to fix preferences that won't save.

That should do it!

Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.

(If you're not using it, switch to the Default theme.)

• Open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.

Once you get the pop-up, just select "'Start in Safe Mode"

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.

To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

Please report back soon.