1 Billion Yahoo User Accounts Stole By Hackers
MEP: Yahoo said it believes hackers stole data from more than one billion user accounts in August 2013, making it the largest such breach in history.
Yahoo said names, phone numbers, passwords and email addresses were stolen, but not bank and payment data.
The number of affected accounts was double the number implicated in a 2014 breach that the internet company disclosed in September and blamed on hackers working on behalf of a government.
The hack revelation comes as telecom giant Verizon is proposing a $4.8 billion acquisition of Yahoo.
The latest disclosures come just three months after the company revealed 500 million Yahoo accounts were hacked in a separate attack.
“An unauthorised party” broke into the accounts, Yahoo said in a statement posted on its website. The company believes the hacks are connected and that the breaches are “state-sponsored”.
The hackers used “forged ‘cookies’” – bits of code that stay in the user’s browser cache so that a website doesn’t require a login with every visit, wrote Yahoo’s chief information security officer, Bob Lord. The cookies “could allow an intruder to access users’ accounts without a password” by misidentifying anyone using them as the owner of an email account. The breach may be related to theft of Yahoo’s proprietary code, Lord said.
Account users were urged to change their passwords and security questions.
