What makes the transport industry so vulnerable to cyber-attacks?

Danish shipping giant Maersk has reported that the recent cyberattack which shut down its computer systems has cost a massive USD200-300 million in lost revenue, due to business interruption.

Maersk is one of the world's top two shipping lines, holding approximately 18% of the global container trade market. The 'Petya' / 'NotPetya' cyber-attack hit Maersk in June 2017, requiring it to shut down a number of its infected networks as a precaution while it took steps to contain the incident. During the shutdown period, no containers were delivered.

Similarly, international logistics company FedEx recently reported that it anticipates significant losses from the Petya attack as a result of lost revenue. FedEx also confirmed that it does not have cyber or other insurance in place to cover these losses.