If you are pointing out a bug in the software and do not need support, I think you should should report it here: https://bugzilla.mozilla.org/ .

Sorry if I misunderstood your post.

@ rxpeters :

In addition to RexPrestige's post :

Am I right assuming that you are talking about this :

http://www.fixtrojan.com/how-to-completely-remove-media-hubs-com-effective-removal-guides/

According to your post you have already ran malware scans (good for you  !), but have you also done this :

Go to the 3-bar menu => Addons => Extensions and look for any unfamiliar or suspicious looking extensions, like e.g.:

SafeSearch Incognito SearchAssist Incognito

When you find any :   remove them.

Also look in : 3-bar menu (or 'Tools') => Options => Advanced => Network tab => Under : 'Offline Web Content and User Data'

Do the same in Windows' Control Panel => Programs.

However :   most malware will be 'hiding' somewhere , so let's run (some more) malware scans :

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.
They all work differently   -   what one program doesn't pick up, the other might.

If, however, you've already done all of the above, you can of course ignore this post.

Do you have the latest version of uBlock Origin yet  ?

https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/

(the system details in your other thread show an older version)