Can you be sure that the logins are successful? It could be that this remote system is just scanning yours and/or running a continuous script to cause denial-of-service or something. One main suggestion is to ensure that you have the latest firmware on your Netgear. You might actually have to blow away the configuration on the router and start from scratch (with your ISP’s assistance of course). This will allow you to start with a clean build since it sounds like the current build/config is suspect. Have you tried asking this question on a Netgear forum or contacting Netgear support?
You should be able to manually configure your router’s IP address. That can be done through the webinterface of the router.
May I ask how you determined the IP was Chinese?
Netgear Router Security Help
Hope this helps!