What is the Hosts file?

Each web site name corresponds to a numerical IP-address on the Internet, which is the "real" address of the computer. When you type a web site name in the address bar of your Internet browser, your computer usually uses a DNS to get the IP of the site.

But there is a way to override DNS entries by using the hosts file. This is a standard file provided in MS Windows. It is similar to a very simple notebook that lists web site names and corresponding IP-addresses. Just two values per web site: name and IP.

The use of the host-file is also very simple. When you are typing a web site name in the address bar of your Internet browser, Windows first of all checks if this name is present in your hosts-file. If it is, Windows uses directly the IP that corresponds to the typed name in the hosts-file. If the name is not in the file, Windows refers a DNS.

A malicious program could modify your hosts-file and replace true IP-addresses with fake ones, leading to absolutely different sites. For example, the IP of the site where you execute your online banking operations can be replaced with the IP of the site's exact copy but actually belonging to criminals.

You may not even notice the difference and will type your user name and password handing them over directly to criminals. Online Armor automatically monitors the hosts file for changes and alerts you to any changes.