You could hack critical infrastructure before AI. Any and all of the bulk internet scanners have had lists of exposed critical infrastructure for quite a while now. At first it was shocking that nothing ever got done about it, then it became routine.
All that AI has done is to lower the bar of entry for criminal activity. Which is a concern, but it's not the primary concern. The primary concern remains that so much critical infrastructure is poorly secured.
All that AI has done is to lower the bar of entry for criminal activity. Which is a concern, but it's not the primary concern. The primary concern remains that so much critical infrastructure is poorly secured.