The 42-year-old, who testified before the Senate Commerce Committee on Capitol Hill in Washington on Wednesday, said the thefts occurred during her almost five-year tenure and she wants to 'sincerely apologize to each and every one of our users'.
But details over who pulled off the more serious 2013 hack continue to elude Yahoo, Mayer said during Wednesday's hearing, which was focused on protecting consumers from future data breaches. A Mayer spokesperson said Tuesday she was appearing voluntarily.
"A combination cooperation between public-private to address this issue is needed", said former Equifax CEO Richard Smith. She said even "robust" defences are not enough to defend against state-sponsored attacks and compared the fight with hackers to an "arms race".
Mayer told the committee that Yahoo fell victim to the breaches despite devoting substantial resources to security in an attempt to stay ahead of sophisticated and constantly evolving threats.
Barros mentioned that Equifax is working on an application that would let customers lock and unlock personal credit data.
'Fifty Shades Freed' Trailer: The Final Climax has Arrived
The movie will also star Kim Basinger , Marcia Gay Harden , Rita Ora , Tyler Hoechlin, Luke Grimes and Brant Daugherty . Ana is threatened by the contractor Christian hires to build their house, Gia Matteo, played by Arielle Kebbel .
Those remarks prompted Committee Chairman John Thune, R-S.D., to ask Mayer why, despite these investments, Yahoo failed to detect the massive 2013 breach for three years. Mayer says Yahoo, which originally said only 1 billion accounts were affected, didn't find out about the hack until it got data from the government in 2016 and still hasn't figured out how it happened, though she says Russian intelligence officers have launched attacks on Yahoo systems.
He said a federal law should replace that patchwork of laws.
'Only stiffer enforcement and stringent penalties will help incentivize companies to properly safeguard consumer information and promptly notify them when their data has been compromised, ' Nelson said.
To this day, she said, security experts have been unable to identify the specific intrusions that led to the breaches: "We don't exactly understand how the act was perpetrated".
Thune told reporters after the hearing the Equifax data breach had created "additional momentum" for Congress to approve legislation.