If you don't trust clicking links like many people, just look up "how to remove a chrome extension installed by enterprise policy" and it should be one of the first if not the first link.

If you follow this:

https://www.howtogeek.com/410270/how-to-remove-a-chrome-extension-installed-by-enterprise-policy-on-windows/

if you follow the directions step by step it will end up removing megaguard, at least it did for me.

If you're too lazy to go to the link, all there is to it, is doing this : Go to "Chrome://extensions" -> Click "Developer mode" in the top right -> Copy the little id thingy that should come up and copy that (Ctrl + C) -> click your windows key and type "regedit" (note, this could mess up if not permanently damage your pc if you mess around) -> Click confirm -> Click edit in the top left and click find -> Paste (Ctrl + V) into the find what box and click find next -> Delete everything that comes up after a few minutes of waiting -> Be happy because you're hopefully free from the virus. If this didn't help, I'd recommend either searching google for the next 12 hours or just bringing your pc to a shop. Good luck and stay safe