Blocking a Site: Mac Cleaner

Hello,

I would like to know if there is a way to block specific websites. Specifically I would like to block the following site: *******

I was playing a game that I had downloaded from the App Store and I got a message that Adobe Flash player needed to be updated. I clicked to update the program and when I double clicked the installer it went to this site and a message that MacCleaner had found 503 errors on my computer and a virus.

I have seen things from Mac Cleaner before and you all helped me to remove their phising software. At the time we also installed MalwareBytes (sp!) I ran a Malware scan and it removed everything that had been installed. But since I always seem to get this issue around this time every year, I am wonding if there is anyway to block this all together?