Your files may be compromised, delete them and upload a fresh install. Change all your server passwords.
And make sure your host knows what is going on, they may be able to help
I'd disagree with that, such a large feature would be better served from the core, or at least an official addon. small features and tweaks should be left to 3rd party addons, but not something that would have to be as large as that
Too late for you perhaps, but not too late for those that still need a solution. I can think of a couple of sites where it would be useful, one of them being a writing site.
Just so we are clear how how WordPress, manages the reviews, the fact of the matter is. They don't, not directly at least. there a a core team of volunteers that handle it. WordPress simple provides the means and the space where it is managed from. but it is a team of unpaid supporters that does...