The internet is not secure, and it seems it really does not matter how secure someone thinks their system is. I mean if the Iranians could hack into a predator drone to land it in their territory and the U.S. and/or Israel could hack into the software that runs the Iranian nuclear facilities to plant a worm, it seems anything could be hacked.
Systems can be hardened. The usual problem is HUMAN fallacies.
No fix for that yet.