Disable WPAD now or have your accounts and private data compromised

Posted on by

WPAD is a protocol, developed in 1999 by people from Microsoft and other technology companies, that allows computers to automatically discover which web proxy they should use. The proxy is defined in a JavaScript file called a proxy auto-config (PAC) file.

The location of PAC files can be discovered through WPAD in several ways: through a special Dynamic Host Configuration Protocol (DHCP) option, through local Domain Name System (DNS) lookups, or through Link-Local Multicast Name Resolution (LLMNR).

Source: Disable WPAD now or have your accounts and private data compromised | CSO Online

The researchers recommended computer users disable the protocol. “No seriously, turn off WPAD!” one of their presentation slides said. “If you still need to use PAC files, turn off WPAD and configure an explicit URL for your PAC script; and serve it over HTTPS or from a local file.”

From Slashdot comments:

To prevent Windows from tracking which network support WPAD, you need to make a simple registry change:

Click the Start button, and in the search field, type in “regedit”, then select “regedit.exe” from the list of results
Navigate through the tree to “HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Wpad”
Once you have the “Wpad” folder selected, right click in the right pane, and click on “New -> DWORD (32-Bit Value)”
Name this new value “WpadOverride”
Double click the new “WpadOverride” value to edit it
In the “Value data” field, replace the “0” with a “1”, then click “OK”
Reboot the computer