Hello. Thank you for coming to JustAnswer.
Sorry for the delay and thank you for your patience. My name is Michael. I will be helping you with your question today.
Please let me know if there as any additional information that you think might be pertinent to your question. If I don't hear back from you, I'll provide the best answer I can based on the information you've given so far. You will still be able to reply with additional information or questions at any point during our conversation, and I'll revise the my answer accordingly.
It is not possible for someone to do this unless they have had access to your phone to install software. If that is the case, there is one way to be sure they do not have access. Change passwords to any accounts you have and do a complete wipe/reset of the phone. And when doing that, do not restore the phone from a backup.
No. It cannot be. They need physical access to your phone