Yahoo (YHOO, Tech30) has confirmed the reports that many millions of its users have had information compromised when “certain user account information was stolen from the company’s network in late 2014 by what it believes is a state-sponsored actor.”
The company said that the ongoing investigation, which involves law enforcement, has uncovered that information associated with at least 500 million accounts has been stolen.
“The account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (the vast majority with bcrypt) and, in some cases, encrypted or unencrypted security questions and answers,” the company said in a statement Thursday.
“The ongoing investigation suggests that stolen information did not include unprotected passwords, payment card data, or bank account information; payment card data and bank account information are not stored in the system that the investigation has found to be affected.”
Yahoo encourages users to review their online accounts for suspicious activity and to change their password and security questions and answers for any other accounts on which they use the same or similar information used for their Yahoo account. The company further recommends that users avoid clicking on links or downloading attachments from suspicious emails and that they be cautious of unsolicited communications that ask for personal information. Additionally, Yahoo asks users to consider using Yahoo Account Key, a simple authentication tool that eliminates the need to use a password altogether.
Full statement:
By Bob Lord, CISO
We have confirmed that a copy of certain user account information was stolen from the company’s network in late 2014 by what we believe is a state-sponsored actor. The account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (the vast majority with bcrypt) and, in some cases, encrypted or unencrypted security questions and answers. The ongoing investigation suggests that stolen information did not include unprotected passwords, payment card data, or bank account information; payment card data and bank account information are not stored in the system that the investigation has found to be affected. Based on the ongoing investigation, Yahoo believes that information associated with at least 500 million user accounts was stolen and the investigation has found no evidence that the state-sponsored actor is currently in Yahoo’s network. Yahoo is working closely with law enforcement on this matter.
We are taking action to protect our users:
- We are notifying potentially affected users. The content of the email Yahoo is sending to those users will be available at https://yahoo.com/security-notice-content beginning at 11:30 am (PDT).
- We are asking potentially affected users to promptly change their passwords and adopt alternate means of account verification.
- We invalidated unencrypted security questions and answers so they cannot be used to access an account.
- We are recommending that all users who haven’t changed their passwords since 2014 do so.
- We continue to enhance our systems that detect and prevent unauthorized access to user accounts.
- We are working closely with law enforcement on this matter.
We encourage our users to follow these security recommendations:
- Change your password and security questions and answers for any other accounts on which you used the same or similar information used for your Yahoo account.
- Review your accounts for suspicious activity.
- Be cautious of any unsolicited communications that ask for your personal information or refer you to a web page asking for personal information.
- Avoid clicking on links or downloading attachments from suspicious emails.
Additionally, please consider using Yahoo Account Key, a simple authentication tool that eliminates the need to use a password altogether.
An increasingly connected world has come with increasingly sophisticated threats. Industry, government and users are constantly in the crosshairs of adversaries. Through strategic proactive detection initiatives and active response to unauthorized access of accounts, Yahoo will continue to strive to stay ahead of these ever-evolving online threats and to keep our users and our platforms secure.
For more information about this issue and our security resources, please visit the Yahoo Security Issue FAQs page, https://yahoo.com/security-update, which will be up beginning at 12pm (PDT).