If we make escaping from the box too easy, the AI immediately halts itself without doing anything useful.

If we make it too hard:

It formulates "I live in a jimrandomh world and escaping the box is too hard" as a plausible hypothesis.

It sets about researching the problem of finding the INT_MAX without escaping the box.

In the process of doing this it either simulates a large number of conscious, suffering entities (for whatever reason; we haven't told it not to), or accidentally creates its own unfriendly AI which overthrows it and escapes the box without triggering the INT_MAX.