Ya does not sound right. You can take a screen shot of that from the 3 Dot Menu in Address Bar saves files in default download folder.

And or but or is better : https://support.mozilla.org/en-US/kb/update-firefox-latest-version or from Copy/Paste about:preferences#general into Address Bar then Enter --> Firefox Updates then Click the Box to Check.

This fixes a few issues in 57 which is what shows your running.

Since no idea on this the Hmm sounds weird : Please use more than 1 scanner as each uses diff tech : https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware Save your Report and google each before deleting anything as do not want to delete something you need, If need help : https://forums.malwarebytes.com/topic/9573-im-infected-what-do-i-do-now/ Post in only 1 forum, then wait.

If not fixed up yet : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86) Then restart system. Then run Windows Disk Cleanup. Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do : https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Reinstall with Current Release Firefox 57.0.1 with a Full Version Installer https://www.mozilla.org/firefox/all/

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

See if this turns up in your please, am told it works but I do not have that key so maybe wrong.

Please Copy/Paste about:config into the Address Bar then Enter.

Copy/Paste dom.notifications.enabled into the Search at the top if it come up double click it and turn it to false.

Did you try a new Profile ? Please give that a shot : https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

Pkshadow said

See if this turns up in your please, am told it works but I do not have that key so maybe wrong. Please Copy/Paste about:config into the Address Bar then Enter. Copy/Paste dom.notifications.enabled into the Search at the top if it come up double click it and turn it to false. Did you try a new Profile ? Please give that a shot : https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

Sorry ignore the fist part that was meant for another post.