This add-on has been causing a lot of trouble on SUMO. It silently changes homepage and search preferences and then "protects" them, changing them back when the user tries to change them. It shows a dialog when it does this (https://people.mozilla.com/~kmaglione/images/b9347a87efe49621.png), however it doesn't seem to work. Clicking the Yes button has no effect no matter which option you choose, and the settings wind up reverting to the Claro settings.
I finally wound up in a situation where the Claro homepage is being enforced even with the add-on and Browser Manager disabled. I have a virtual machine snapshot, so I'll try to figure out the details.
Ok, as far as I can tell, it's the Browser Manager service (mngr.exe) doing this. This thing is ridiculously evil. If you kill the process, it respawns. If you try to stop the service, not only does it fail, but if you've previously set it to Disabled, it changes itself back to Automatic. We should report this thing to AV vendors.
Sorry for the spam. That's confirmed. Disabling the service then restarting properly kills it and the homepage stops resetting itself at that point.
Thanks for staying on top of this. I agree that this thing is pure evil.