There is no such thing as an infinitely strong string. If we do have access to infinitely strong string then there's no telling what other physics-defying stunts we'll be able to pull, so I vote maybe we can pull the thing out of the black hole with our infinitely strong, infinitely long string that passes through an infinite number of pulleys that multiply any input force by infinity. So actually even a child could pull stuff out of the black hole.

Basically you need to jot this down: through God all things are possible