hello, this sounds like a problem possibly caused by adware on your pc.

1. please go to the firefox menu ≡ > addons > extensions & remove any suspicious entries (toolbars, things that you have not installed intentionally, don't know what purpose they serve, etc).
2. also go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there.
3. finally, run a full scan of your system with different security tools like the free version of malwarebytes & adwcleaner, which are specialised in adware and browser hijackers.

Remove a toolbar that has taken over your Firefox search or home page Troubleshoot Firefox issues caused by malware

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 ask 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.