London: Yahoo Japan faced a hack attack, which reportedly led to a theft of 22 million user ids that constitutes one tenth of its 200 million members.
A file of ID details was stolen from the administration system at Yahoo Japan, which was spotted late on 16th May.
In a report by BBC, the tech firm cut the net access as soon as it detected the attack. Although the firm was not sure if the data had been stolen, it did not ''deny the possibility''.
Though the file did not contain the information, which may potentially be used to impersonate users, the firm tightened security measures and was investigating to ensure the attacks are not repeated.
The firm was also contacting users to change their login passwords, the reports added.