Host Database
/private/etc/hosts“This file force resolves IP addresses to domains. It's not used nearly as much as it used to be. Some security software will even use this file to redirect known malicious IP addresses to nowhere so that the malware is unable to communicate with its command and control server.”
You can open this file using Text Edit, but OS X may not automatically select that application so you must direct the computer to use that application with the following command.
open –a “textedit” /private/etc/hosts