Quit Safari. Then go to
System Preferences > Network
Click the padlock at the bottom, enter your Admin Id to unlock it. Then click 'Advanced...' and hit the 'DNS' tab. Remove the DNS address(es) with the +/- buttons at the bottom and replace with Google's DNS server
8.8.8.8
Click 'OK' and close System Preferences (command-Q).
Flush the DNS cache by opening Terminal.app and pasting this into the Terminal window:
sudo killall -HUP mDNSResponder
press 'return' on your keyboard, then enter your admin password, which will be invisible when you type it (so type carefully).
Restart Safari and test.
If the problem persists, open the /etc/hosts/ file by typing this in Terminal
sudo vi /etc/hosts
Look for any lines that mention either google.com or apple.com. Highlight them with the mouse and 'control-c' to copy. Past them as a response here. You can close the vi page by
first hitting the 'esc' key, then typing
:q
(that's a colon and a 'q') then pressing 'return'. Quit Terminal.
Best Answer
The Safari web browser has extensions you can load that will warn you about dangerous websites. The one I use is called URL Advisor. Another one is SafeSurf. If you go to "Safari Extensions" under the Safari menu item you can get a list of available extensions.
I don't know for sure about Google Chrome or Firefox but if extensions exist for Safari I feel confident they exist for other browsers as well.