How can I insert promotional messages during a WhatsApp conversation?

Question

Information Security

During WhatsApp calls, ads were inserted into the conversation, while the content of the audio ad message corresponded to the topic under discussion. Whatsapp client downloaded from play store...

Answer 1

The policy states that all correspondence, including audio and video communications, is used by Facebook for analysis and use for advertising purposes.
Do you still want to be surprised?
Write or send a voice message with the text of a well-known platform for websites or a car, and you will see ads on Instagram

Answer 2

By way of a completely wild guess: maybe one of you has leaked some kind of malware that is able to catch the moment when the call is set and the microphone is used? And then he turns off the microphone and drives his audio to you and the interlocutor.
Obviously, something like this is possible, at least locally, on one device - for example, when sports trackers tell you about the next kilometer, stopping both local music and radio.