Yahoo disclosed today that attackers in 2013 stole data associated with more than 1 billion accounts. CISO Bob Lord said this incident is “distinct” from a 2014 attack in which 500 million accounts were breached.

Yahoo’s latest SEC filing includes confirmation that it knew attackers were on its network in 2014 and stole information on 500 million accounts.

Experts challenge Yahoo’s assertion that state-sponsored hackers were behind a 2014 breach that resulted in 500 million lost records.

Yahoo confirmed that in 2014 state-sponsored hackers stole information associated with 500 million accounts from its network.

Yahoo is expected to confirm a data breach that exposed hundreds of millions of credentials dating back to 2012.