Yahoo hack steals personal info from 500 million accounts, in biggest email raid

Computer hackers swiped personal information from at least 500 million Yahoo accounts in what is believed to be the biggest digital break-in at an email provider.

The massive security breakdown disclosed Thursday poses new headaches for beleaguered Yahoo CEO Marissa Mayer as she scrambles to close a US$4.8 billion sale to Verizon.

The breach dates back to late 2014, raising questions about the checks and balances within Yahoo — a fallen internet star that has been laying off staff and trimming expenses to counter a steep drop in revenue during the past eight years.

At the time of the break-in, Yahoo’s security team was led by Alex Stamos, a respected industry executive who left last year to take a similar job at Facebook.

Yahoo didn’t explain what took so long to uncover a heist that it blamed on a “state-sponsored actor” — parlance for a hacker working on behalf of a foreign government.

The Sunnyvale, California, company declined to explain how it reached its conclusions about the attack for security reasons, but said it is working with the FBI and other law enforcement. Yahoo began investigating a possible breach in July, around the time the tech site Motherboard reported that a hacker who uses the name “Peace” was trying to sell account information belonging to 200 million Yahoo users.