[Android Central Question]

So recently my phone (Sony Xperia XZ Premium) has been calling a specific contact on my phone list without ringing it up, however the call is not registered in my phones logs nor is it registered by the service provider. The other person's phone (an iPhone 6) does register the call but does not ring.

There is a voice message that is left however it seems to be an unauthorised recording from some other time during the past 2 or 3 days. For example yesterday at 4 in the morning the other person received a voicemail recording from the day before at around midday when we were on a family picnic, and no one had used my phone that day. This is concerning because it feels like someone is recording my day to day activities.

My service provider says that it may be a problem with the other persons phone because the next day she received another voicemail but from a private number this time and in the audio people were speaking in a foreign language (not indian, sounded like chinese). So could that mean that my phone is being used by someone else for spam or could it be malware from some of the apps that I downloaded the day before the picnic?