Today I noticed in my server logs there are thousands of requests for the following files
/wp-content/uploads/2012/10/mailer7.php /wp-content/uploads/2012/10/keymailer.php
When I checked the folders there are more files possibly suppor files for this script. It looks like sending mass emails from this script.
I was wondering how it was possible to upload those files there.
Any tiny bit of information would be helpful to avoid this in future.