What happens if someone has your ISP ADDRESS?

Hello Chris. First off, what is the operating system on the computer you are using, and what Norton product do you have installed and its version as well? Also, please post a screenshot of EXACTLY what you are seeing, whether within your router or Norton history. Here is how. This will allow us to see what you are seeing.

Secondly, report the attack on your IP address that is assigned, to your internet provider so they can investigate at their end. If this type of attack is making it to your ISP provided router / combo device, the ISP isn't doing their job to screen for it service side on their end. 

Thirdly, see if your ISP or personal device has an available firmware update and install it. IF you have never changed the default login username and password to access the settings of your ISP device I would do so immediately. Do the same for your WiFi SSID's and passcodes if they have never been changed from factory defaults. If you can provide us with some info about what your ISP device is, your providers name and your personal routers make and model ( if you are using one ) we can help with that as well. 

Cheers