"PHPMailer continues to be the world's most popular transport class, with an estimated 9 million users worldwide. Downloads continue at a significant pace daily." http://phpmailer.worxware.com/You can find more information about the exploit here:
"Probably the world's most popular code for sending email from PHP! Used by many open-source projects: WordPress, Drupal, 1CRM, SugarCRM, [..], Joomla! and many more" https://github.com/PHPMailer/PHPMailer
Please be sure to update your website at the earliest to prevent remote execution of codes leading to your web site being hacked. Since this is a PHPMailer code bug we would be unable to directly help you on this. Your script provider should be able to help you on this.
Friday, December 30, 2016