While websites routinely are under constant attack. Everything is under attack. Recently a worker was managing a water treatment facility remotely and noticed it was not working properly. It became apparent that somebody has gained access and started dumping lye in vast amounts into the water supply. Lye is not toxic but it can damage pipes due to the alkaline nature.
Apparently the worker was using TeamViewer which is used for remote access. In June 2016, hundreds of TeamViewer users reported having their computers accessed by an unauthorized address in China and bank accounts misappropriated. The company said it was due to careless and weak passwords. TeamViewer is a subscription based package starting at $58 per month.
Using cryptographic grade passwords and certificates are needed to protect important infrastructure. This way valid users are authenticated properly.