The NightOwl application has existed since 2018 and is used to automatically switch between light/dark modes on the operating system. It is an alternative to the built in macOS automatic mode which only switches when the user steps away from the computer.
However, the application has been bought out by “TPE.FYI LLC” in late 2022 that forcibly joins your devices into a botnet for use of market research, without your knowledge (other than the TOS in small text on the download page) or express consent (this feature cannot be turned off, even when the app is quit). This is documented in their terms of service.
Vigilance. Resource monitoring and network traffic monitoring. The occasional scan with anti malware tools to catch known bad actors.
I use malwarebytes when someone needs a scan, though they got naggy enough that I uninstalled it right after using it for my grandfather. Other monitoring IDK. LittleSnitch is popular on Mac but I have no personal experience with it.