Did you try to reboot the computer to see if that has effect?

You can check if you have an "Old Firefox Data" folder on the desktop in case the Refresh feature in Firefox has been used and a new profile has been created.

• https://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

I don't understand what you're saying though.... This happened like an hour ago, no I didn't reboot yet and I'm scared to reboot, but like why the hell all my saved sites and logins will dissappear from that box? I didn't click CLEAR or anything, what would cause that?

Look on the computer's desktop. Is there a folder named Old Firefox?

No, I typed in the search old firefox nothing came up but where can I search that?

Please Check with :

• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data See if you have 2 Profiles and check the dates of the Folders if have to Right Click and Properties.

The oldest will be your original Profile with the info in it but it may have become corrupted and that is why a new Profile was Created.

Please make copies of the folders and never work with originals you do not want to corrupt anything further.

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

For Future :

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Please let us know if this solved your issue or if need further assistance.

I see there are two folders but one says December 17 and the other one December 21 when the passwords and logins got wiped. The weird thing is that the other one shouldn't be December 17, it should be way older, this is very weird! it's 'cause I got hacked on December 17 but I don't think my PC got infected. I'm not sure why mozilla wiped the logins. How can I know if the December 17 one is corrupted?

Also, if there's a new one on December 21st, why there are still some usernames that was saved (but not passwords).

Saved passwords can disappear when the involved files can't be accessed for some reason by Firefox (files might be in use by other software). In such a case a reboot might help to clear up this situation, just like it might help in other situation where you notice erratic behavior (a Firefox restart and a reboot are part of the first Troubleshooting steps).

You can copy the logins.json and key3.db files from the "Old Firefox Data" folder on the desktop to the current profile folder to recover the passwords.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

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

You can copy files like these with Firefox closed to the current profile folder to recover specific data.

• bookmarks and history: places.sqlite
• bookmark backups: compressed .jsonlz4 backups in the bookmarkbackups folder
• cookies.sqlite for the cookies
• formhistory.sqlite for saved form data
• logins.json and key3.db (decryption key) for Passwords saved in the Password Manager
• cert8.db and possibly cert_override.txt for (intermediate) certificates stored in the Certificate Manager
• persdict.dat for words you added to the spelling checker dictionary
• permissions.sqlite for Permissions and possibly content-prefs.sqlite for other Site Preferences
• sessionstore.jsonlz4 for open tabs and pinned tabs

astorian said

it's 'cause I got hacked on December 17 but I don't think my PC got infected

Well, just in case,

You may have ad/mal-ware. Further information can be found in this article; https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.