Cascading Effect: One Attack Led To Another At Yahoo

Russian hackers working with Russian spies didn’t crack Yahoo security all at once.

Instead, according to an account offered by U.S. officials, they methodically made their way deeper into Yahoo’s network over the space of months - maybe years. That allowed them to forge technological skeleton keys that would unlock many Yahoo accounts, steal personal information and then use that data to break into other email services used by their targets, U.S. officials said in announcing charges against four Russians .

That Department of Justice indictment fills in some of the blanks surrounding a massive security breach that occurred in 2014, but Yahoo didn’t reveal until six months ago. But it doesn’t answer why it took Yahoo so long to grasp its seriousness or why it waited so long to tell its users - or Verizon, which is paying $4.5 billion for Yahoo operations now tainted by the biggest security lapses in internet history.

Yahoo declined to comment beyond a statement thanking law enforcement for its efforts.

It’s also not clear whether the Russian hackers and spies involved in the Yahoo break-in were also involved in other recent hacking attacks, such as the leak of embarrassing emails from the Democratic National Committee during the 2016 election. U.S. intelligence agencies have previously said they believe that Russian hackers were involved in those breaches, too.

SECOND-BIGGEST BREACH

“We are in a cyberwar and our government hasn’t woken up and done anything about it,” said security analyst Avivah Litan of Gartner Inc.

Although the Yahoo attack compromised more than 500 million user accounts, the hackers appeared mainly interested in sifting through the email of Russian and U.S. government officials, Russian journalists and employees of financial firms and other businesses, according to the indictment.