MSC-FAL.1-Circ.3 - Guidelines On Maritime Cyber Risk Management (Secretariat) International Maritime Organisation IMO
2017

These Guidelines provide high-level recommendations for maritime cyber risk management. For the purpose of these Guidelines, maritime cyber risk referes to a measure of the extent to which a technology asset is threatend by a potential circumstance or event, which may result in shipping-related operational, safety or security failures as a consequence of information or systems being corrupted, lost or compromiesed.

Available here
guideline, recommendation