Samsung phones seem to be trying to take over the world, messaging random users' contacts and sending them messages and photos. The problem turned up on Reddit, spotted by Gizmodo, and then found its way to Samsung's official forums.
The messages in question are being sent through the default Samsung Messages app, with reports stating that the app doesn't show users the files were sent. The only way people know this is happening, is once they receive a response from the recipient of the message sent. One user said that his Galaxy smartphone sent ALL of his photos to his girlfriend.
The Verge talked to a Samsung spokesperson who said they are "aware of the reports" and that their technical teams are "looking into it". The forums seem to say that both the Galaxy S9 and Galaxy S9+ are affected, but there could be more.