Hi, open the 3-bar menu > Add-ons > Extensions, and look for/remove/disable anything you don't recognise, because it may be masquerading under a different name.

You can also check your Firefox Desktop shortcut for corruption: Right click on it > Properties, and in Target, make sure there is no sign of anything other than Firefox. If there is, delete that part of it. Or if it's easier, you can just delete it and recreate a new shortcut. More: Wrong home page opens when I start Firefox - How to fix.

Another thing you can do, is to look in your PCs Control Panel for any recently installed programs that you don't recognise. What is search hijacking?.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller (for more info, see this alternate TDSSKiller download page)
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

If your question is resolved by this or another answer, please take a minute to let us know. Thank you!

Just a follow-up, Yahoo should not be taking over Firefox, because they are not our search partner, Google is in most countries. So some other software is hijacking your search engine.

It turned out to be an extension, something like Yahoo weather report. Thank you!

Tyler Downer said

Just a follow-up, Yahoo should not be taking over Firefox, because they are not our search partner, Google is in most countries. So some other software is hijacking your search engine.

Scribe said

Hi, open the 3-bar menu > Add-ons > Extensions, and look for/remove/disable anything you don't recognise, because it may be masquerading under a different name. You can also check your Firefox Desktop shortcut for corruption: Right click on it > Properties, and in Target, make sure there is no sign of anything other than Firefox. If there is, delete that part of it. Or if it's easier, you can just delete it and recreate a new shortcut. More: Wrong home page opens when I start Firefox - How to fix. Another thing you can do, is to look in your PCs Control Panel for any recently installed programs that you don't recognise. What is search hijacking?. You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller (for more info, see this alternate TDSSKiller download page)
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Further information can be found in the Troubleshoot Firefox issues caused by malware article. If your question is resolved by this or another answer, please take a minute to let us know. Thank you!

None of this seems to apply to my situation. I am on a Mac, nothing new installed, nothing I don't recognize in plugins and extensions, no search engine choices except yahoo. WTF how do I get rid of yahoo!

Tyler Downer said

Just a follow-up, Yahoo should not be taking over Firefox, because they are not our search partner, Google is in most countries. So some other software is hijacking your search engine.

what do I do to remove yahoo as my search engine? In my preferences>search yahoo is my only choice. I don't have yahoo installed as an extension or add on. I haven't downloaded anything new and there is nothing in my extensions or add-ons I don't recognize. Help. it has been days now and it is very frustrating.

Hi IVR4, you jumped into a different thread yesterday afternoon and I replied to you there. Did you already try this:

Hi IVR4, some users have encountered a problem with built-in search engines vanishing from their Options/Preferences page. Have you already tried using the "Restore" button here:

• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Windows: "3-bar" menu button (or Tools menu) > Options
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the left column, click Search, and then on the right side, scroll down to the bottom of the "One-Click Search Engines" box and try the "Restore Default Search Engines" button.

Does Google come back?

If not:

You may need to remove a Firefox settings file and let Firefox regenerate it. Here's how:

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 Return

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-release, double-click it to display the contents of that profile folder.

Leaving that window open, switch back to Firefox and Quit out (for example: Firefox menu > Quit).

Pause while Firefox finishes its cleanup, then rename search.json.mozlz4 to something like searchOLD.json.mozlz4.

Start Firefox back up again. It should rediscover the built-in search engines and allow you to check and modify the default.

Does that work?

That did it!!! Searching for help for this problem was a task in and of it self.

Thanks

I also cannot get rid of Yahoo - it keeps coming back. I have removed all search engines from the list except Google and I have made Google the default and Yahoo still comes back. I have tried the extensions and the only one I have is FaceBook Container I have tried looking for MalWare and found nothing and I have removed all cleaner apps. I also get a dialogue that pops up saying that "Apple Wants to make Changes" and to please fill in a password. This happens about once a day and while I always press cancel I cannot find the source of this dialogue. However I am pretty certain that the two things are connected. I have also tried renaming search.json.mozlz4 to something like searchOLD.json.mozlz4. Thank you for your help

Hi buzzard724, which of the following is closer to the behavior you see?

• You set Google as your default search engine on the Preferences page, but the setting changes to a different search engine. What is listed as the default search engine after the change?

• You set Google as your default search engine on the Preferences page, and Firefox's search box/address bar drop-down show that searches will be sent to Google, but searches actually appear on a different site. What is the full URL of a sample search results page?

Maybe check the connection settings in case there is where it goes wrong.

You can check the connection settings.

• Options/Preferences -> General -> Network: Connection -> Settings

See "Firefox connection settings":

• https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

Thank you jscher2000 - behaviour is closest to your first suggestion. The context is that I have deleted all search engines except google. From memory when Yahoo shows up again the search preferences are set to Yahoo as the default search engine and below there is still a choice of Google but Yahoo is chosen. As this is from memory it may be slightly weirder with Google as the deault still but Yahoo as the chosen engine (maybe)

To answer cor-el's question the Network Connection settings have just one thing checked: "Use System Proxy Settings"

Thank you both - fingers crossed this makes sense

Hi buzzard724, what is the URL of a sample Yahoo results page? The parameters might point in the direction of a particular family of malware.

Meanwhile, you mentioned it happens about once a day. Is it when you start Firefox, or start your Mac, or is more like a scheduled function that occurs at a particular time?

Thank you Jscher, I have been waiting for it to happen again - and it just has! This is the url generated when I searched in the address bar for "ytest"

https://uk.search.yahoo.com/yhs/search?hspart=Lkry&hsimp=yhs-SF01&ts=sy&type=ANYS_A0468_set_bfr&obt9bpdyed=0&p=ytest&param1=na3P9yVrJGqvPvD8aa5-HxZSn--q2zX99s_0IxZaJ-8I1bMSp1WKF3_XOXdeDTbFlHnH1QsUAfJLQb9R-JrpM06G9B8kql_C1B1mEOVjpJ1pbSqcs64qe-__3mgdPe2HVI8S0H6InOrSQ-laxdPwx5U42hGILitqVVH8MyUszT3zk33CMB1p0PeUo74KWVPLJrOG5Oi0uh7liYheWhC0nAkbjaR_8hakBIE-srOZaUk%2c

Previous browsing activity was facebook and then bbc.co.uk I was kind of waiting for it to happen becasue the Apple Password dialogue popped up this morning three times (it's always three times)

I am also posting a screenshot of the Firefox Preferences for search engine. Previously only Google would have been present. Magically "BrowserDefault" has reappeared.

Hi buzzard724, malware on your system could be injecting changes into Firefox's settings. A popular scanning/cleaning tool for Mac users is: https://www.malwarebytes.com/mac/

Please also double-check:

(A) No new, unknown, or untrusted extensions (details below).

(B) No autoconfig files. This thread has an example of how to track that down: https://support.mozilla.org/questions/1256067

Extension Check

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 that mentions search, or that you just do not remember installing or why? If in doubt, disable (or remove).

Any improvement?

Again thank you I will test these later today. Worrying or Interesting - Chrome now has the same issue: https://uk.search.yahoo.com/yhs/search?hspart=Lkry&hsimp=yhs-SF01&ts=sy&type=ANYS_A0468_ext_bcr_T&obt9bpdyed=0&p=precision+calculator&param1=na3P9yVrJGqvPvD9i55M4GWgPYjaweauFlPHRqKLhMJJTmXaH0dc-RwoXVJA2AfOXZY9_8_hWo8kkGC-te0KHd8CF80wOubsOG9FElCBp1YKtj-7tya6WEY_lGcPD6g_UrZot_VvfUrC5YIhny5NqB6AaAgUiLxuzd1AUndv5XA8Tz4qBlsIxACEMGr5f4FAD8QmtK1hOoLqZtP9vmG1-bK5771wFOQm1N84Qpc4EtdZJtd1

I will update as I try your suggestions

Scribe said

Hi, open the 3-bar menu > Add-ons > Extensions, and look for/remove/disable anything you don't recognise, because it may be masquerading under a different name. You can also check your Firefox Desktop shortcut for corruption: Right click on it > Properties, and in Target, make sure there is no sign of anything other than Firefox. If there is, delete that part of it. Or if it's easier, you can just delete it and recreate a new shortcut. More: Wrong home page opens when I start Firefox - How to fix. Another thing you can do, is to look in your PCs Control Panel for any recently installed programs that you don't recognise. What is search hijacking?. You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller (for more info, see this alternate TDSSKiller download page)
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Further information can be found in the Troubleshoot Firefox issues caused by malware article. If your question is resolved by this or another answer, please take a minute to let us know. Thank you!

Thank you!!! I was going nuts... I discovered something called SweetSearch (I think - deleted it so can't remember!) in control panel/programs and features. Deleted it, and also a couple of firefox extensions I wasn't sure might be causing the problems and which I didn't really use. Just tried a new search and beloved Google search is back!!! Thank you for your help.

1) In the search settings of Chrome it says: "MacTrusted is controlling this setting" I have removed it as an Extension - does it live elsewhere on my Mac? 2) Malware bytes removed a few issues - please see attached image. 3) The only extension I have in Firefox is FaceBook Container and cannot find

• SafeSearch, SearchAssist Incognito,

FileConverter Addon, SearchLock, DiscreteSearch, WebSearch, Findwide Search Engine, securedsearch

4) I have no add-ons in Firefox - other than the two in the image that have been disabled for a while - I would like to remove them cannot see how to do this? 5)/Applications/Firefox.app/Contents/Resources/defaults/pref - I only have a file named channel-prefs.js - so should be good

I have set all back to Google as default and for the last week all has been quiet. Malware Bytes has quaranteed these files (see attached screenshot) and I can only presume (thank you Malwarebytes) that this has made the difference. Thank you very much for your help. Paul

In Firefox 63+ you can check the about:policies#active page to see whether policies are active.

• https://support.mozilla.org/en-US/kb/customizing-firefox-using-policiesjson