Write some Software

We have some pdf files we don't want to the user download freely, but they can view it anytime and also print it whenever they want. For us, doesn't matter if the user send it to print to a PDF Printer (like Primo PDF or others), but we wan't to block download possibility as Google PDF Viewer do. Our platform is developed on Microsoft ASP NET 4.5, MVC 4.5. It's hosted on our servers over W2012SVR. It's fully developed including user access controls, shopping cart, buyers history and so... but we need to have control over PDF's downloads. We imagine there's a right way to create an OCX or Google Chrome Extension (in this case we will force to our users to work over Chrome).