Unexpected Safari Extension -- Download Video After a very recent install-from-scratch of Mojave, I was installing a Safari extension and noticed one already there called "Download Video". 



It claims to be version 1.0.0 and that it "Downloads video from a webpage". It was not active (i.e. its box in the Extensions manager was unchecked) but I've no idea how it got there. I certainly didn't knowingly do it myself

I did notice one other inactive extension -- "Open in Internet Explorer" -- that I also did not explicitly install myself. However, it says it came as part of Parallels Desktop and I did install that. So that leads me to conclude that the installation of certain apps may also involve installation of Safari extensions. And I certainly have installed some apps since after my clean Mojave install, so maybe the Download Video thing piggy-backed in off one of those? But most of what I've installed is fairly well-known, standard stuff -- MS Office, Emacs, and the like. Nothing I'd expect to have a sneaky video downloader hanging off it. 

Any idea where in could have come from?

Safari 12.0.2
Mojave 10.14.2
MacBook Pro (Retina, 15-inch, Mid 2015)
If I had to guess on what this was there would be two things that I would guess that it might be:

Adware


You might have accidentally installed a package somewhere that installed this as an option in the installer, and this would install adware that could change your default search browser. The person who made the extension might have messed up and not made it so that it didn't activate it. 


Real youtube downloader


At one point you might have installed a browser extension if you wanted to download a youtube video. These are everywhere and since youtube does not have a built in free system to download the videos officially, there are a ton of different 3rd party plugins that people have developed and this might be one. If you can remember that you installed it then you shouldn't worry.


Either way, I would uninstall it if you don't use it anymore as it could be anything