Hi, if you are able to, open the 3-bar menu > Add-ons > Extensions, and look for/remove/disable anything you don't recognise.

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 search for the malware in your PC's search box and programs - look for any recently installed programs that you don't recognise.

Try a Clean Reinstall; this means you remove your Firefox program files and then reinstall Firefox. This process does not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location (AppData). With Firefox closed, use another browser to download Firefox from https://www.mozilla.org/en-US/firefox/all/ and save the file to somewhere convenient on your computer.

Now delete the Firefox installation folder which should be in one of the following locations -

C:\Program Files\Mozilla Firefox C:\Program Files (x86)\Mozilla Firefox

You can now double click the file you previously downloaded to install Firefox.

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.

Did this fix your problems? Please report back to us. Thank you!

hi

thanks for your reply. The malware was on one specific webpage which froze (hijacked) the whole browser.

I was able to access the Refresh Firefox option in a dialogue window which had opened somehow - so I restarted Firefox. My bookmarks were saved, I only had to redo my browser settings.

This was a very nasty malware - I got it last year, exactly the same one. It sits on some popular webpages that you are likely to open from the Google link. I'm positive that if I clicked on one of those windows it opened, it would release a ransomware.

Last year it went away after restarting my PC. The hackers must have updated it as this time only restarting the browser has got rid of it.

What happened with the malware protection apparently inbuilt in Firefox? How come the browser and my Bitdefender have completely missed it?

thanks

Ah OK. Install uBlock Origin, it is known to be good at preventing that happening https://addons.mozilla.org/firefox/addon/ublock-origin/

thanks for the link - but when I read the reviews they talk about ad blocking.

Will it detect a malware webpage and stop it from loading?

Also, does it work only on incoming webpages or also on outgoing i.e. will it block any content (not ads) on my website from people visiting my site?

Hi again

On a related issue - my Firefox account.

When I wanted to sign in to sort out the malware issue, Firefox has pre-populated the form with one of my email addresses with which I created a password and set up an account as I was in a hurry.

I now tried to change my email address associated with this account, but when I entered it in the account settings, it said that this account already exists. I then recalled that I already have an account with that email address - to which I'd like to revert.

How can I retain this conversation thread in my other account if I delete this one (to keep just one)?