My hosting server gave me this reply
xmlrpc.php script is quite commonly installed with many free blogging. Unfortunately, it is quite easy to exploit and often abused by amateur 'hackers' and spamming groups for malicious purposes.
A number of plugins still use xmlrpc.php and the solution is normally to rename the xmlrpc.php file to another file name. However Jetpack requires the file to always be called xmlrpc.php and these changes won't work.
Is there anything can be done?