Verizon, the new parent company of Yahoo, announced on Tuesday that all 3 billion of its accounts were affected by an August 2013 data theft. This is in addition to the 1 billion accounts that Yahoo previously said was affected by the breach. 

Yahoo said that it took action in 2016 to protect all 3 billion of its accounts from breaches upon leaning of the data theft. 

Verizon said it is sending email notifications to the additional affected user accounts. Yahoo's investigation indicates that the user account information that was stolen did not include passwords in clear text, payment card data, or bank account information, the company said in a statement. The company is continuing to work closely with law enforcement, Verizon added.

"Verizon is committed to the highest standards of accountability and transparency, and we proactively work to ensure the safety and security of our users and networks in an evolving landscape of online threats," said Chandra McMahon, Chief Information Security Officer, Verizon. "Our investment in Yahoo is allowing that team to continue to take significant steps to enhance their security, as well as benefit from Verizon's experience and resources."