Hi I am not a great advisor on this matter, do you have a wireless network or is it all wired if it is wireless then someone my be hacked into your system via your wireless network, if this is the case i am sure someone on here can help you with your problem but if you are hooked up wireless you need to stop using it until you get your problem taken care of, maybe just use a wired hookup until then, hope this helps   have a great day    Terry