Ticket offices closed in stations but online services continue to work as normal.
A suspected cyber attack on Italy's state railway company has disrupted ticket sales, Ferrovie dello Stato announced on Wednesday.
The company said it had discovered evidence of what could be "phenomena linked to a cryptolocker infection" on its computer network on Wednesday morning, reports La Stampa newspaper.
This has led to the temporary closure of ticket booths and the deactivation of self-service ticket machines in stations, as a precautionary measure.
Online ticket services are operating as normal. Trenitalia has said that passengers can board trains and purchase tickets directly from the conductor without any surcharges.