Yahoo started warning users about suspicious activity of their accounts in 2015 and 2016, the company confirmed on Wednesday. However, not all of the users notified by Yahoo have been compromised in one of the two massive data breaches the Sunnyvale-based firm suffered in 2013 and 2014. The Internet company didn't reveal how many people it's notifying about suspicious account activity, but all of the notified users received an identical message referring to "forged cookies," data strings which allow someone to log into their account without re-entering a password. Affected users were told that Yahoo believes someone may have used forged cookies to access their accounts between 2015 and 2016. Media outlets are speculating that the fact Yahoo isn't willing to disclose the number of affected users means a significant portion of the company's customers were compromised.
The two hacking attacks against Yahoo resulted in unknown hackers stealing email addresses, answers to security questions, birth dates, and other user data from over a billion people. The Internet firm initially accused foreign states of sponsoring the attacks against its servers but has yet to elaborate on these accusations. Yahoo already started notifying users who it believed were compromised during the attacks back in December, but the company has now increased its notification efforts due to pressure from Verizon, industry sources say. Likewise, the investigations concerning the aforementioned data breaches are also close to being finished, a source with knowledge of the matter told TechCrunch.
Verizon can afford to pressure Yahoo to wrap up its internal dealings as quickly as possible seeing how the largest wireless service provider in the United States is currently in the process of acquiring the Sunnyvale-based company. Furthermore, Verizon reportedly managed to use Yahoo's troubles to negotiate a $250 million discount on its acquisition, meaning the firm will likely pay around $4.55 billion for Yahoo. In the meantime, Yahoo is still under a lot of heat from both consumers and authorities. The company was previously criticized for not being transparent about the massive data breaches it suffered, and the U.S. Securities and Exchange Commission (SEC) even started an investigation of the company's dealings with investors. An update on the situation is bound to follow in the coming weeks as Verizon finalizes its acquisition of Yahoo.