So I had installed Avast free antivirus (2015) on my macbook (2014, with OS X Yosemite), and it's messed up my computer. It made it so that a number of my websites that I commonly browse were blocked, so I removed the application with the help of AppCleaner and manually removed a load of documents and packages connected to avast from my computer. In retrospect I probably should have made use of the uninstaller, but I only discovered there was an uninstaller after I deleted the app. Now even more sites in my browser are blocked and can't be accessed in any way. I've been looking in my system to figure out if there were still avast documents, but I can't find any, and I'm at a loss. Thankfully I have an ipad, so I can compensate with it, but it's a nuisance.