I'm not sure I agree. The purpose of the passive voice is to promote or bring into focus the object or "patient" argument. In this case, the topic is really One

I'm not sure I agree. The purpose of the passive voice is to promote or bring into focus the object or "patient" argument. In this case, the topic is really OnePlus' systems the fact that its security was compromized. The identity and nature intruders is not the focus and is probably not even known, so the passive voice makes sense.