ClassPad is Casio's education web app, and the server contains hundreds of thousands of "items" belonging to individuals and organisations around the globe. Since 18 October, more than 91,921 items belonging to Japanese customers have been pinched, including individuals and 1,108 educational institution customers, and 35,049 items belonging to customers from 148 other countries.

The data included customers' names, email addresses, country of residence, purchasing info, order details, payment method and license code, and service usage info, including log data and nicknames.

Casio noted that it doesn't retain customers' credit card information, so presumably, people's banking info wasn't compromised in the hack.

An employee discovered the incident on 11 October and noticed that some of the network security settings in the development environment had been accidentally disabled.

Casio believes these were the causes of the situation that allowed an external party to gain unauthorised access."

According to Casio, the intruder didn't access the ClassPad.net app.