Yahoo says another billion user accounts were hacked in possibly the biggest hack of all time

Yahoo CEO Marissa Mayer

Reuters/Pascal Lauener

Yahoo CEO Marissa Mayer

Yahoo has announced that "more than one billion user accounts" may have been stolen by hackers during an attack that took place in August 2013, according to a press release.

This is a separate hack than the one that Yahoo announced back in September, in which as many as 500 million user accounts were compromised.
With a billion accounts at risk, that would make this the biggest breach of all time - bigger than the Myspace breach of 360 million user accounts and 427 million passwords.
"The company has not been able to identify the intrusion associated with this theft," Yahoo says.

This story is developing. Refresh for updates.

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