This is why you need to undertake the very first line of defense with your home router. These days it's not just those of us in tech that have self-managed wireless routers in our homes. You can buy them anywhere.
What are the first things you should do when you set up your new router? #1 Change the admin credentials, never keep default credentials in place. #2 Turn off remote administration which oddly enough for so many routers the default is ON. You want to be able to admin your router ONLY if you are physically connected to it via an Ethernet cable. If you are savvy enough and want to have remote administration on then you should be aware of the issues involved.