hello norman587, this sounds like a problem possibly caused by adware on your pc. please go to firefox > addons > extensions & remove any suspicious entries (toolbars, things that you have not installed intentionally, don't know what purpose they serve, etc). also go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there and run a full scan of your system with the security software that you have in place and different other tools like the free version of malwarebytes & adwcleaner.

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

Thanks

All I could find was an extension called Microsoft .NET assistant as I have no idea what that is I've disabled it.

I'll let you know if the Australian Brewery scam reappears

Norman

This is from PC World. Easy way to remove it and other malware. Download Malwarebytes (free version and it's safe). Run a quick scan first. That will probably find it. Then check off all malware found. It should be gone. My first scan found 69 malwares. Removed all including staticaustralianbrewing company, Best wishes.