The only way that I am aware of to get those cookies back would be to use a file recovery software. Below I will list ones that are free and that I have used in the past to recover accidentally deleted files. Actually using these programs is something I cannot help you with on these forums, hope this helps, Good luck!!

https://www.piriform.com/recuva

http://download.cnet.com/Restoration/3000-2094_4-10322950.html

http://www.shadowexplorer.com/downloads.html

https://www.softperfect.com/products/filerecovery/

Try to restore a previous version of the cookies.sqlite file.

• Right-click: Properties > Previous Versions
• http://windows.microsoft.com/en-US/windows7/Previous-versions-of-files-frequently-asked-questions

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox
• https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile

See also:

• http://kb.mozillazine.org/Profile_backup
• https://support.mozilla.org/kb/Backing+up+your+information

Thank you for the respond! I tried to restore files by using a restoration program. I tried to replace the files in my Firefox profile, but it didn't worked.

I don't have a copy of my mozilla profile, nor a back up file :(

I think that password can't be restored, unfortunately.

Firefox 32 and later builds store the passwords in the logins.json file in the profile folder and no longer use the signons.sqlite file that has been used before (the matching key3.db file is still needed). If you still have the signons.sqlite file used in previous Firefox versions then you can try to force Firefox to migrate passwords saved in this file (you will lose passwords saved in logins.json by Firefox 32+ versions). You can force Firefox to reimport the passwords from the signons.sqlite file and rebuild the logins.json file with these steps:

• reset the signon.importedFromSqlite pref on the about:config page to the default value via the right-click context menu
• delete the logins.json file in the Firefox profile folder with Firefox closed

When you restart Firefox then you should have the signon.importedFromSqlite pref with the value set to true and you should have the passwords imported in the Password Manager unless there may have been errors.

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config