Yahoo Japan Corp said it detected an unauthorized attempt to access administrative system of its web portal site Yahoo! Japan. Reportedly, the organization also suspects that as many as 22 million user Ids might have been leaked, as per the report Kyodo news agency.
"We don't know if the file (of 22 million user IDs) was leaked or not, but we can't deny the possibility given the volume of traffic between our server and external" terminals, the company said in a Reuters report lately.
However, the breach did not contain any information on the passwords or the user data necessary for identity verification to reset passwords.
Reportedly the company detected the access attempt on May 16 around 9 PM, according to Kyodo. Similar attempts were made on Yahoo system on April 2, since then Yahoo tightened the screws on it's systems monitoring.