This post highlights the Cyber attack involve 4 well known seaports in the world.
Below are the links to the Maersk, COSCO, Port of Barcelona, Port of San Diego Cyber Attack.
Moller-Maersk puts cost of cyber attack at up to $300m
Long Beach Port terminal hit by ransomware attack
Port of Barcelona suffers a cyberattack that impacted many of its servers
Port of San Diego Hit by Cyberattack
Most of them were attacked by ransomware. One obvious fact in these attacks was the ransomware targeted Windows 7 and below.
The better solution for now is upgrade the machines to Windows 10 as many as possible. Alternatively, you can convert some of the machines to Linux. Of course, it does not mean ransomware will not attack Windows 10 and Linux forever. It is just to lower the risk for now.