Hosts (file) - Extended Applications

Extended Applications

In its function of resolving host names, the hostsfile may be used to define any hostname or domain name for use in the local system. This may be used either beneficially or maliciously for various effects.

Redirecting local domains

Some web service and intranet developers and administrators define locally defined domains in a LAN for various purposes, such as accessing the company's internal resources or to test local websites in development.

Internet resource blocking

Specially crafted entries in the hosts file may be used to block online advertising, or the domains of known malicious resources and servers that contain spyware, adware, and other malware. This may be achieved by adding entries for those sites to redirect requests to another address that does not exist or to a harmless destination (e.g. localhost).

Various software applications exist that populate the hosts file with entries of undesirable Internet resources automatically.