I read a sci-fi novel back in the 90’s that had as its plot line, the Internet becomes Self-Aware, and intends to take over...................
These things are mindless: they are essentially a result of searching, sorting and counting - and physical actions taken as a consequence of combinations of these.
Machines have no judgment and they NEVER will. Machines can only follow existing algorithms - they cannot truly understand and they cannot create anything truly new.
Once a vulnerability is found, one can use it on all the rest - and they will all fall the same way.