Hello Ishini,

So what may have happened is many things. I'm going to ask you to search for malware on your system.

Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

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
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.

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

Did this fix your problems? Please report back to us, Michael.

Thank you for the quick reply. I'm afraid it didn't helped. I use AVG antivirus Free 2014, regularly check the system with uVS. According to your suggestion I checked with TDSSkiller and ESET Online Scanner. Now I wonder if FF have a backup of "key3.db" and other files that contain my logins and passwords somewhere?

sry, lag

Hi Ishini, No problem. Firefox would not keep a back up of "key3.db" anywhere. So, if you want to recover your passwords, try to use the following tool.

• Piriform Recuva

Just download the free trial and attempt to recover the "key3.db" file. Just point it to your Firefox installation directory.

This should solve your problem, but there is no guarantee that the file will be there.

So, if this helped, mark it as helpful, so other users who are facing the same or similar issues, can resolve their problem as well.

Have a good one, Michael.

Thank you. But I looked for the wrong file. "logins.json" was damaged and "logins.json.corrupt" appeared in profile folder. I replaced "logins.json" with an old one (I made a back up a year ago) and the list of of logins and passwords appeared. I think many logins are lost, but with the old one and corrupted file i think I'll be able to fix it. Passwords are ok, only logins are missing. Thank you for suggestions :)

Nope, I was too optimistic on the point. "logins.json.corrupt" is empty, though it's bigger then an old one "logins.json.corrupt", and passwords are old :( Will have to spend some time to recover every thing. But at least a part of all is saved. :)

Hello,

I am glad to hear that your problem has been resolved. If you haven't already, please select the answer that solves the problem. This will help other users with similar problems find the solution more easily.

Thank you for contacting Mozilla Support.