The suspicious activity was spotted by the company in June – an unauthorised access to the network was detected.

Mitsubishi Electric stated that email exchanges with the Defense Ministry and Nuclear Regulation Authority and files concerning cooperation with railways, car manufacturers and utilities have been exposed.

The personal data of 8,000 people who are looking for a vacancy in the company, work and worked for the firm has been compromised.

The announcement was made only now due to the complicacies of the investigation process – the violator deleted activity logs which hindered the identification of transferred files.

The investigation is ongoing.