Firefox does not change your default search engine, and even if we did, the default for Firefox is Google, so why would we switch you away?

It's possible some malware is doing this, I recommend a scan with mawarebytes.org

Which of these is closest to what you see:

(A) After you make Google your default, Firefox uses it until the next time you exit out, then when you start up again, your default was switched to Yahoo (what's the exact name of the default search engine?)

(B) After you make Google your default, it can change at any time, even during the same session

(C) Even when Google is your default search engine, Firefox sends all searches to Yahoo instead (what's a sample results page URL for the Yahoo results page?)

One possible culprit would be an extension. You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Command+Shift+a (Windows: Ctrl+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions.

Then cast a critical eye over the list on the right side. Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything suspicious or that you just do not remember installing or why? If in doubt, disable (or remove).

Any improvement?

Hello, I went to Extensions and the only there is Google Analytics Opt out Add on..nothing else.

Firefox is still doing it, every few days it switches from google search engine to what it calls Browser default, defined as Yahoo.

Any other suggestions? Thank you

Please do the following (Yahoo isn't the Firefox default, so this should never be happening):

• Make sure you are running Firefox 60.0.1 or later. Update Firefox to the latest release
• Refresh Firefox. Refresh Firefox - reset add-ons and settings
• Make sure you have no malware on your machine: Troubleshoot Firefox issues caused by malware

SB18 said

Firefox is still doing it, every few days it switches from google search engine to what it calls Browser default, defined as Yahoo.

Actually as of Firefox 57.0 and later any locales of Firefox that had Yahoo as one of the default search engine options was changed back to Google. As of Firefox 59.0 and 52.7.0esr and later Releases the Yahoo search engine was completely removed and not just hidden. https://blog.mozilla.org/blog/2017/11/14/firefox-features-google-as-default-search-provider-in-the-u-s-canada-hong-kong-and-taiwan/

https://hg.mozilla.org/releases/mozilla-release/rev/a46d7b315f70

Little public information on the real reason(s) for the complete removal however Mozilla and Yahoo have been in a legal dispute for some months now. https://blog.mozilla.org/blog/2017/12/05/mozilla-files-cross-complaint-against-yahoo-holdings-and-oath/

So Firefox 57.0, 58.0, 59.0, 60.0 downloads from mozilla.org or www.mozilla.org/firefox/all/ and updates does not come with Yahoo as a search engine option on any locale anymore.

The getting changed to Yahoo or what appears to be a Yahoo search engine is due to some other means outside of Firefox adding the search engine or due to malware or due to an extension you installed.

For a time there were some people who got a malware called Yaahoo for example.

SB18 said

Firefox is still doing it, every few days it switches from google search engine to what it calls Browser default, defined as Yahoo.

That's a strange name for a search engine!

Usually this is a problem with an "affiliate" -- Yahoo and other sites pay software distributors when you load a page with an address that contains their affiliate code. Such unwanted features may be installed along with free software and if you keep the free software bundle, the problem may reoccur over and over.

If the malware clean-up doesn't resolve it:

It might help to discover where the search engine loaded from. This is a little bit difficult to discover because the information is stored in a compressed file. Here's how you can read out the contents of the file:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" Help > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, on the Profile Folder row, click the "Show in Finder" button. If Finder highlights an icon with a semi-random name like a1b2c3d4.default, double-click it to display the contents of that profile folder.

Leaving that window open, switch back to Firefox and open this page on my site:

https://www.jeffersonscher.com/res/searchjson.html

Arrange Finder so you can see the box on that page, and then drag and drop search.json.mozlz4 onto the box.

After a few moments, a script in the page should list out the search engines in the file. What does it show for the mystery item?