Multiple Remote devices

This seems like a security flaw to me.. at least dealing with a remote access trojan.. had i Been using this and got it via phone outside my network I would have likely lost the router.. maybe permanently as these hackers have put custom firmware or modified versions everywhere printer Xbox phones modem pc components can this be disabled. Or can I use a Linux system to spoof a phone to run the app.. I do not want a device with a tons of networking features that I don't use and that travels and uses other access point holding the keys to the castle.