By simulating an attack originating from a mobile app/client-side vulnerability that gains additional permissions by running a kernel or root exploit, Zimperium was able to uncover Secret Chats that were readable in plain-text in the process memory, as well as in a Cache4.db file.
Additionally, once a chat was deleted, the user may think that it cannot be retrieved by anyone who is trying to read the Secret Chat’s content; however, an attacker can still obtain the content of the messages.

удобно+надёжно