Yandex conducted its own investigation, which showed that one out of three people who had access rights "necessary to provide technical support for the service" was involved in the data leak of almost five thousand Yandex mails.
Access to these mailboxes is currently blocked. The owners have been advised that they need to change the password for their accounts.
The company expresses regret about what happened. Yandex promised to revise the work processes of employees who have administrative rights of this level of access.
The company has already applied to law enforcement agencies.
It's worth reminding that earlier in the search engine Yandex were found personal data of Russians: train tickets, payments, passport scans. Yandex has assigned responsibility for the disclosure of personal data to the owners of the sites where such information was posted.