Bad news for Yahoo users again. Last September the company informed about a data breach affecting 500 Million user accounts. Now the company reveals a new data breach where 'unauthorized third party' accessed data from more than 1B Yahoo user accounts.
Advertising
It's just unbelievable, what Yahoo just revealed. Law enforcement provided Yahoo with data files that a third party claimed was Yahoo user data. External forensic experts analyzed this data with the assistance from Yahoo and found that it appears to be Yahoo user data. The company 'believes' an unauthorized third party stole data associated with more than one billion user accounts in August 2013.
In other words: Yahoo wasn't aware about the hack till the data was offered. And Yahoo shows they know nothing for sure – just "we believe". And: Yahoo have not been able to identify the intrusion associated with this theft. They believe this incident is likely distinct from the incident we disclosed on September 22, 2016.
The outside forensic experts have identified user accounts for which they believe forged cookies were taken or used. The stolen user account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (using MD5) and, in some cases, encrypted or unencrypted security questions and answers. The investigation indicates that the stolen information did not include passwords in clear text, payment card data, or bank account information. Payment card data and bank account information are not stored in the system the company believes was affected.
Yahoo claims they have informed affected users and recommends to change their passwords and security questions and answers for any other accounts on which you used the same or similar information used for your Yahoo account. Now we have a 500 million user account breach in 2014 and a 1 billion user account breach in 2013. What else is in stock with Yahoo and data breaches? Now it seems that Verizon, who decided to buy Yahoo, have to rethink this deal. Below is the full Yahoo announcement of the latest data breach.
Important Security Information for Yahoo Users
Advertising
By Bob Lord, CISO
Following a recent investigation, we've identified data security issues concerning certain Yahoo user accounts. We've taken steps to secure those user accounts and we're working closely with law enforcement.
What happened?
As we previously disclosed in November, law enforcement provided us with data files that a third party claimed was Yahoo user data. We analyzed this data with the assistance of outside forensic experts and found that it appears to be Yahoo user data. Based on further analysis of this data by the forensic experts, we believe an unauthorized third party, in August 2013, stole data associated with more than one billion user accounts. We have not been able to identify the intrusion associated with this theft. We believe this incident is likely distinct from the incident we disclosed on September 22, 2016.
For potentially affected accounts, the stolen user account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (using MD5) and, in some cases, encrypted or unencrypted security questions and answers. The investigation indicates that the stolen information did not include passwords in clear text, payment card data, or bank account information. Payment card data and bank account information are not stored in the system the company believes was affected.
Separately, we previously disclosed that our outside forensic experts were investigating the creation of forged cookies that could allow an intruder to access users' accounts without a password. Based on the ongoing investigation, we believe an unauthorized third party accessed our proprietary code to learn how to forge cookies. The outside forensic experts have identified user accounts for which they believe forged cookies were taken or used. We are notifying the affected account holders, and have invalidated the forged cookies. We have connected some of this activity to the same state-sponsored actor believed to be responsible for the data theft the company disclosed on September 22, 2016.
What are we doing to protect our users?
We are notifying potentially affected users and have taken steps to secure their accounts, including requiring users to change their passwords. We have also invalidated unencrypted security questions and answers so that they cannot be used to access an account. With respect to the cookie forging activity, we invalidated the forged cookies and hardened our systems to secure them against similar attacks. We continuously enhance our safeguards and systems that detect and prevent unauthorized access to user accounts.
What can users do to protect their account?
We encourage our users to visit our Safety Center page for recommendations on how to stay secure online. Some important recommendations we're re-emphasizing today include the following:
- Change your passwords and security questions and answers for any other accounts on which you used the same or similar information used for your Yahoo account;
- Review all of 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; and
- Consider using Yahoo Account Key, a simple authentication tool that eliminates the need to use a password on Yahoo altogether.
For more information about these security matters and our security resources, please visit the Yahoo Security Issue FAQs page, https://yahoo.com/security-update.
Statements in this press release regarding the findings of Yahoo's ongoing investigations involve potential risks and uncertainties. The final conclusions of the investigations may differ from the findings to date due to various factors including, but not limited to, the discovery of new or additional information and other developments that may arise during the course of the investigation. More information about potential risks and uncertainties of security breaches that could affect the Company's business and financial results is included under the caption "Risk Factors" in the Company's Quarterly Report on Form 10-Q for the quarter ended September 30, 2016, which is on file with the SEC and available on the SEC's website at www.sec.gov.
Advertising
