On Wednesday 14 December, Yahoo warned that it had uncovered yet another massive cyber attack, this time around reporting that data from more than one billion user accounts was compromised back in August 2013, making it the largest breach in history. The number of affected accounts is 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.
News of that September attack, which affected at least 500 million accounts, prompted Verizon Communication Inc to state in October that it might withdraw from an agreement to buy Yahoo’s core Internet business for $4.83 billion (£3.8 billion).
Following this latest disclosure, Verizon stated: “We will review the impact of this new development before reaching any final conclusions.”
A Yahoo spokesperson told Reuters that the company has been in communication with Verizon during its investigation into the breach and that it’s confident the incident will not affect the pending acquisition.
Yahoo required all of its customers to reset their passwords: a stronger measure than it took after the previous breach was discovered, when it only recommended a password reset.