Ad URL Bad Boy List

Use this list with a local nameserver.  You can use this list with windows to block ads.  To do this, download the list hosts format and put it in your C:\Windows\ folder (C:\WinNT\system32\drivers\drivers\etc\ under Windows 2000 and I think NT as well) as a file called "hosts" (just "hosts, no .txt or anything).  If you already have a file called "hosts" there, add this list on to the end.

how it works

Every time your machine sees a hostname (like ""), it has to lookup the IP address before it can contact that host.  The first place it looks for the address is your hosts file, which can contain a list of hostnames and corresponding IP addresses.  Most big websites use some kind of system for ads where the images are stored on a particular server.  If you list that server in your hosts file with a bogus IP address, your computer won't be able to load the ad image.

The IP address  is a special address that always points to the machine you're using right now ("localhost").  You can specify any address, but is guaranteed to fail.


  1. You visit a web page and your browser downloads the html for the page.
  2. Part of the html says that the ad image at the top of the page is stored at
  3. Your machine looks up the hostname "", and sees that it points to
  4. Your machine tries to find the banner on itself (i.e.: the IP, and the banner ad fails to load.


See for more information:

Blocking ad servers with hosts files and by DNS

hosts file information

Open Directory - Proxy Filtering Ad Filters

Web Ad Blocking