I use TeamViewer on my home lan under free "personal use" license. I don't
believe there's a way to connect remotely to a computer that runs it without
alerting the user and giving them the option to kick the "intruder" off.
It's a help desk product, not a security product.
I will say that I haven't studied every way to configure it, or every way it
can be hacked, but I am surprised that it is flagged as a PUP unless no one
at MBAM knows much about it and their attitude is "Let the user make an
exception."