The 2013 Yahoo data breach was already the largest data breach in U.S. history, now it has been confirmed that it was even larger than first thought.
Verizon has now confirmed that rather than the breach impacting approximately 1 billion email accounts, the 2013 Yahoo data breach involved all of the company’s 3 billion email accounts.
Prior to the disclosure of the 2013 Yahoo data breach, a deal had been agreed with Yahoo to Verizon. The disclosure of a 1-billion record data breach and a previous breach impacting 500 accounts during the final stages of negotiations saw the sale price cut to $4.48 billion – A reduction of around $350 million or 7% of the sale price. It is unclear whether this discovery will prompt Verizon to seek a refund of some of that money.
Verizon reports that while Yahoo’s email business was being integrated into its new Oath service, new intelligence was obtained to suggest all of Yahoo’s 3 billion accounts had been compromised. Third party forensic experts made the discovery. That makes it the largest data breach ever reported by a considerable distance, eclipsing the 360 million record breach at MySpace discovered in 2016 and the 145 million record breach at E-Bay in 2015.
The data breach involved the theft of email addresses and user ID’s along with hashed passwords. No stored clear-text passwords are understood to have been obtained, and neither any financial information. However, since the method used to encrypt the data was outdated, and could potentially be cracked, it is possible that access to the email accounts was gained. Security questions and backup email addresses were also reportedly obtained by the attackers.
The scale of the cyberattack is astonishing, and so is the potential fallout. Already there have been more than 40 class action lawsuits filed by consumers, with the number certain to grow considerably since the announcement that the scale of the breach has tripled.
Verizon has said all of the additional breach victims have been notified by email, but that many of the additional accounts were opened and never used, or had only been used briefly. Even so, this is still the largest data breach ever reported.
The 2013 Yahoo data breach was investigated and has been linked to state-sponsored hackers, four of whom have been charged with the hack and data theft, including two former Russian intelligence officers.One of those individuals is now in custody in the Untied States.