How to edit the hosts file

September 2016


How to edit the hosts file

The hosts file (/etc/hosts on Unix based system) is the first step in the translation of a FQDN hostname to the IP address format.
When making a DNS request on any address server on the web, this file is queried first. For each name present in this file, a connection will be opened to the defined IP address. It works just like a telephone directory.
  • If that address is 127.0.0.1 (my PC) the connection will be made on localhost
  • If a server exists on your PC, it will access the latter. If the server doesn't exist, nothing happens.

The IP address of the localhost is written as:
  • IPV4 : 127.0.0.1
  • IPV6 : ::1

On devices with IPv6 enabled, so you can use both. You can modify the hosts file to block access to certain websites.

Why changing the hosts file?

The hosts file is viewed each time you connect to a website, much like a directory of addresses. If the site is listed in the hosts file and has its IP address set to 127.0.0.1, then access will be blocked. By cons, if the website isn't listed in the hosts file, your ISP will automatically connect you to the IP address of the requested website. By modifying the hosts file, you can:
  • Prohibit access to certain sites,
  • Accelerate access to your favorite website (for which you know the IP address).

How to modify the hosts file?

The hosts file is located here:
C:\WINDOWS\system32\drivers\etc\hosts
A clean hosts file looks like this:
  
# Copyright (c) 1993-2009 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mappings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host

# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost


To edit the hosts file:

To block a website using the host file:
  • Type the IP address, followed by a TAB space and the website name.

127.0.0.1    gromozon.com           
127.0.0.1 xearl.com
127.0.0.1 td8eau9td.com
127.0.0.1 mioctad.com
127.0.0.1 mufxggfi.com
127.0.0.1 uv97vqm3.com
127.0.0.1 coeds.com*
127.0.0.1 lah3bum9.com*
127.0.0.1 cvoesdjd.com*


Once completed, your file should be like this:


You can add all the addresses you want, but if your hosts file becomes too large, it may cause some issues with the DNSClient service of Windows (which puts the svchost process at 99% in your Task Manager). You can disable this service if you wish to use a large hosts file:
  • Click on Start > Run
  • Type services.msc
  • Select DNSClient > "Disable"


You can also make use of a predefined template. E.g the MVPS hosts file: 26,000 entries.
  • Some addresses are blocked in your firewall (IP Range).
  • To summarize, when you try to connect to a listed website, the computer will redirect to 127.0.0.1 (your computer's IP)
  • Try pasting the 127.0.0.1 in the explorer.


195.225.176.0 - 195.225.179.255          
85.255.112.0 - 85.255.127.255
66.230.175.0 - 66.230.175.255

How to restore the hosts file to its default values

Some malwares tend to modify the hosts file, redirecting you to another server, usually an infected one. They can also block access to websites, such as online anti-virus.
O1 - Hosts: 0.0.0.0 boxore.com =>Adware.Boxore
O1 - Hosts: 0.0.0.0 www.boxore.com =>Adware.Boxore
O1 - Hosts: 0.0.0.0 boxore.org =>Adware.Boxore
O1 - Hosts: 0.0.0.0 www.boxore.org =>Adware.Boxore
O1 - Hosts: 0.0.0.0 boxore.net =>Adware.Boxore
O1 - Hosts: 0.0.0.0 www.boxore.net =>Adware.Boxore
O1 - Hosts: 0.0.0.0 dlmanager.com =>Adware.Boxore
O1 - Hosts: 0.0.0.0 eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 www.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 dist.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 file.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 log.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 ads.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 prof.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 soft.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 upd.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 dfr.eorezo.com =>PUP.Eorezo
O1 - Hosts: 0.0.0.0 lollipop-network.com =>Adware.Lollipop
O1 - Hosts: 0.0.0.0 www.lollipop-network.com =>Adware.Lollipop
O1 - Hosts: 0.0.0.0 download.lollipop-network.com =>Adware.Lollipop
O1 - Hosts: 0.0.0.0 offers.lollipop-network.com =>Adware.Lollipop

You can use one of the below softwares to restore the hosts file:

Myhosts (by jeanmimigab)

  • Its main advantage is its compatibility Windows 95 / 98 / ME / 2000 / XP / Vista / 7.
  • Just download it and run it.
  • Note: No need to disable UAC or run as administrator under Vista / 7.
  • Official Website

RstHosts (byXplode)

  • RstHosts is compatible with Windows 95 / 98 / ME / 2000 / XP / Vista / 7 (x86 and x64)
  • Download here .
  • Start, then click Restore.

Hoster


Rogue Killer


Related :

This document entitled « How to edit the hosts file » from CCM (ccm.net) is made available under the Creative Commons license. You can copy, modify copies of this page, under the conditions stipulated by the license, as this note appears clearly.