Hi Phil..and everyone who is concerned with this issue. . .
I have experienced the same thing. No one given me an explanation that makes sense as to why random devices appear on my network. In my case, I noticed that they only appear when I log in and only with OS8.1.
At first I thought it was someone who hacked into my network but those devices never appeared on my router. As a precaution, I changed my router and stopped broadcasting my SSID so I could verify that no one had logged onto my network except for me. This
did not make a difference.
I tried everything to try and figure out what was causing this and these are my findings.
i began keeping track of what devices were appearing. I took the MAC addresses that appeared with those devices and searched them on the web since it's all I could go by.
The search results indicate to me that it is malicious. Everything came back as Spyware, Trojan, Virus, and Backdoor activity. On other searches it was cell phone carriers based out of Aruba (which is all out of the ordinary), fake AV, etc.. I suspect that
whatever it is, it is super stealthy and undetectable or at least undefined.
since I've noticed various devices alternating from day to day, feel that it is a super virus that deconstructs itself and reassembles somewhere in affected networks but I can't explain how.
I've run several antivirus, malware, and misc other detection software but they have only let me down. I've spoken with MS level 2 technicians who have run diagnostic tests as well but found nothing, or very little but at least, they can testify to this
phenomena. unfortunately, they don't know what it is either. Only thing I know is that there is no remedy apparently so, or at least for the time being.
please let me know if you find out anything else, if you find a way to get rid of this, or if this is a 8.1/10 vulnerability.
good luck!