This link will explain what ms-pptapp
. Do you have your computer Port Forwarded
? If you don't know if you are or not you may have a whole in your secruity. This would be a possible access to take control of your entire computer from a remote location.
I am not a security experts here, but I do know if you did not set this up, someone has access to your computer.
I would activily block the internet with a firewall till you can work this out. IMO.http://www.schneier.com/pptp-faq.html