Seicomart: unauthorized access to the Seicomart app

At Seicomart, a convenience store chain mainly in Hokkaido, one account was found to have had its club card cancelled without authorization on the night of 24 September, and on 28 September it found that a third party may have reached the member data server through the app server. Names, genders, birth dates, addresses, phone numbers and emails of about 570,000 accounts may have been viewed. No passwords leaked and it holds no card data. It cut off the server at 20:00 on 28 September and stopped new sign-ups, My Page logins and other functions.