We have to be so careful these days to protect our internet and any tool can be helpful. Bitdefender is a security package that I rate and they offer a free home scanner to anyone.
Download the program and it will look for any other devices on your home network, followed by a detailed scan of them all.
The first question to ask yourself is ‘do I recognize that has been found?’. That sounds easy if the device name is “someone elses iphone” but not so good for ‘alertme.com limted’ which turned out to be my Hive Thermostat.
Having finished the scan, it tells you of any vulnerabilities that it has found. In my case I needed to update the firmware on my router.