SAN FRANCISCO — Yahoo said hackers stole personal information from 500 million of its user accounts, a massive security breakdown it attributed to a “state sponsored actor.” The breach disclosed Thursday, the latest setback for the beleaguered internet company, dates back to late 2014.
That’s when high-tech thieves hacked into Yahoo’s data centers, the company said. But Yahoo only recently discovered the break-in as part of an ongoing internal investigation.