Yahoo’s security team knew a state-sponsored hacker had hacked certain user accounts in 2014, an internal investigation found. But some senior executives allegedly failed to comprehend or investigate the incident further. Yahoo also learned of an even bigger hack that affected 1 billion Yahoo user accounts last year. The internet company is facing about 43 class action lawsuits over the 2014 breach, a new filing said. The findings were made in a Yahoo securities exchange filing on Wednesday that offered more details about the breach. In a separate post, Yahoo CEO Marissa Mayer said she’ll forgo taking her annual bonus because the breach happened on her watch.”]