Is it possible to create a hidden call recording application for nokia s40?

Question

Java

Hello.
Tell me, please, is the subject theoretically possible and, if so, how to make sure that the phone is clean (or not). In no case do I plan to create anything like this, therefore I am only interested in a theoretical possibility. There are programs on the Internet that claim such functionality, but it does not seem at all that the phone actually supports such features (serious tasks performed in the background). In addition, there is an important condition - nothing suspicious in the list of applications. I'm leaning towards it being impossible, but that's just a guess, it would be great to hear confirmation or rebuttal from someone in the thread.
Thank you.

Answer 1

s40 - rather weak .... s60 - maybe.