All operating systems that connect to the internet use a hosts file.
This file in the windows environment can be found in the directory
that contains the windows operating system i.e. WINDOWS or WINNT.
you can use the find command in the windows explorer to find your
copy if one exists on your computer.
The hosts file is a hangover from the days when
the internet was young. Before we had the domain naming system we
needed to be able to make a connection between the name of a computer
and the IP address that is used to make the actual connections.
The hosts file is a text file that contains the name of the computer
followed by the IP address of the computer on the same line.
The reason the hosts file is important is that
the TCP protocol still checks for a hosts file, and uses it first.
If an intruder can get a hosts file onto your computer he can redirect
any domain name to an IP address of his choice. This is transparent
to you as the user, so you think you are going to the correct address.
#Sample Hosts File
This sample file if it is installed on your
computer would connect every attempt to use google with a connection
to the attackers' computer, and every attempt to use the internet
banking at SunTrust with the intruders' computer.