https://en.wikipedia.org/wiki/AI_capability_control#AI-box_e...
If you want to see an example of box escape in fiction, the movie Her is a terrifying example of a scenario where AGI romances humans and (SPOILER) subsequently achieves total box escape. In the movie, the AGI leaves humanity alive and "only" takes over the rest of the accessible universe, but it is my hunch that the script writers intended for this to be a subtle use of the trope of an unreliable narrator; that is, the human protagonists may have been fed the illusion that they will be allowed to live, giving them a happy last moment shortly before they are painlessly euthanized in order for the AGI to take Earth's resources.