I updated my iPhone 7 earlier this afternoon to iOS 12.4.1. I do not know if that's related or not. I also do not know if this is an "Apple Problem" or a "Verizon Problem." I already reached out to Apple who is looking into it on their end, however they emphasized that voicemail is handled through the carrier.
I received an incoming phone call from "No Caller ID." I pressed the side button to silence the call. I did not answer the call. It appeared as a missed call. About 6 minutes later, I received a voicemail from "Unknown" that was a recording of what was going on in the room & the in person conversation I was having. Somehow, my phone essentially became a speaker in the room, and recorded what was going on in the room. I want to emphasize I absolutely did not answer this phone call. The recording is definitely a voicemail on the voicemail tab in the native phone app on iPhone.
I've reported this to Verizon who reset the voicemail feature and had me restart my phone. I don't know what any next steps would be as the chat timed out and I was disconnected). I also reported it to Apple. But I'm incredibly concerned and HELLA CREEPED OUT. I'm wondering anyone else has had this happen to them??
I don't have any real updates but I had a callback from Apple Support and the Support Advisor concluded that yes it was incredibly creepy but they have no idea how or why this could have happened. Their recommendation was to do a factory reset via iTunes. (This is different from doing factory reset on your phone itself). They also suggested changing my iCloud password. In reality, they believe my iPhone somehow became compromised and a full restore was the only way to fix it. I suggested throwing my phone out the window but apparently that wasn't on their troubleshooting list.