I have been seeing messages EXACTLY the same as these in english and now a different language. So either someone is somehow guessing my password, i am seeing other people's chats, or (far fetched idea) somehow someone has cracked you security and is using a program to allow users to submit gtp4 questions to random accounts without having to pay... (totally made it up, but in this case it could happen. 0.0000001% chance)
Be in all seriousness, this is a serious issue and we do need a response on if this is a bug or security issue on our side. There is nothing to help use figure it out.