that is possible with the right tool. Nowdays to find an FUD RAT is almost impossible all are outdated and detected - but if you have skill you can create your own an you can use it until it got detected and uploaded to antivirus database . Is better to start do reasearch and keep trying ! stay safe !
It's certainly possible but would be quite difficult and most likely cost quite a hefty sum. I personally am not equipped do take on such a task nor can I recommend anyone, but I'm just letting you know.