How to control other smartphone camera with which malware & how it can be undone ?

[AC Question]

A friend of mine got a trozan, or other malicious software installed by other. Someone has been tracking all her smartphone activities and also remotely recording from the camera under her nose. How this can be undone ? How is he doing all these; monitoring and the camera controlling stuff ?

 

[mhinc]

A friend of mine got a trozan, or other malicious software installed by other. Someone has been tracking all her smartphone activities and also remotely recording from the camera under her nose. How this can be undone ? How is he doing all these; monitoring and the camera controlling stuff ?

There is absolutely no way to have done this unless the phone was rooted, and typically installed by the person doing the "viewing"
I would guess it's someone your friend knows.
Factory reset would be the first start to removing the malware.