Please ensure that you have the latest version of MailPoet installed that does not contain the known file upload vulnerability.
http://blog.sucuri.net/2014/07/remote-file-upload-vulnerability-on-mailpoet-wysija-newsletters.html
http://blog.sucuri.net/2014/07/malware-infection-breaking-wordpress-sites.html
http://blog.sucuri.net/2014/07/mailpoet-vulnerability-exploited-in-the-wild-breaking-thousands-of-wordpress-sites.html
What exactly is? /wp2014/wp-cron.php Do you have a cron job setup in your host control panel? Is this coming from the plugin?