Here’s my take on this.
Looking for signs like unusual battery drain, increased data usage, and unexpected device behavior are definitely good starting points. You might notice your phone getting hot for no reason or taking longer to shut down. It’s also smart to regularly check your list of installed apps and their permissions. An unfamiliar app or one with extensive permissions (like access to your microphone and location) that doesn’t need them could be a red flag.
On the other hand, it’s worth remembering that these symptoms can have other causes. A buggy software update or a legitimate app running in the background can also drain the battery and use data. Advanced monitoring tools are often designed to be discreet, leaving a very small footprint. So, while these manual checks are helpful, they aren’t always conclusive.