Web Proxy Auto-Discovery & Proxy auto-config

TL;DR

This site serves a Proxy auto-config (PAC) file that configures browsers to contact websites directly, without using a (possibly malicious) proxy.

It eliminates the risk of a higher level domain serving a file that directs your traffic to their proxy.

More Information

The Web Proxy Auto-Discovery (WPAD) Protocol is a method used by clients to locate the URL of a Proxy auto-config (PAC) configuration file using DHCP and/or DNS discovery methods.

While greatly simplifying configuration of one organisation's web browsers, the WPAD protocol can open doors for attackers to change what appears on a user's browser.

Files served here:

• wpad.dat for DNS lookups - the reason for this site - served with MIME type application/x-ns-proxy-autoconfig
• Copy in wpad.da for broken Internet Explorer version 6.0.2900.2180.xpsp_sp2_rtm
• Copy in proxy.pac - conventional file name for DHCP configurations

Our very simple Proxy auto-config (PAC) JavaScript functions:

// Legacy
function FindProxyForURL(url, host)
{
  return "DIRECT";
}
// IPv6-Aware
function FindProxyForURLEx(url, host)
{
  return "DIRECT";
}

For more information, and source code, see github.com/clifford2/web-wpad.