So even if your default search engine is set to Google (as described in the support article "Change your default search settings in Firefox"), you get Bing results when using Firefox's search bar or address bar?

That sounds like it could be either a bad add-on or a redirect virus. I am not very familiar with Mac cleanups, but for Firefox add-ons, please try this:

Open Firefox's Add-ons page using either:

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

In the left column, click Plugins. Set nonessential and unrecognized plugins to "Never Activate".

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. Bear in mind that none of these came with Firefox, they are all optional.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac:<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Remove Bing Anything. Now do the same in the computers Programs Folder.

Windows: Start > Control Panel > Uninstall Programs. Mac: Open the "Applications" folder. Linux: Check your user manual.