Yahoo hacking scandal: BT investigating impact of 'state-sponsored' hacking on its customers

BT is investigating whether its customers may be affected by the “state-sponsored” hacking of 500 million Yahoo accounts.

Personal data has been stolen from the accounts in a security breach which dates back to 2014 but was discovered only recently.

The stolen data includes names, email addresses, telephone numbers, birth dates, hashed passwords, and the security questions — and answers — used to verify an account holder’s identity.

Last month, the technology site Motherboard reported that a hacker who uses the name Peace boasted he had account information belonging to 200 million Yahoo users and was trying to sell the data on the web.

BT, which has used email services provided by Yahoo, said: “BT is currently investigating the Yahoo data breach. As a precaution for the minority of our customers who use Yahoo mail, we are advising those who haven’t changed their passwords post-December 2014 to change them.”

Sky, whose email service is powered by Yahoo, told customers: “We advise that you change your passwords online and follow good password management practices.”

Customers have attacked Yahoo for not discovering the hack in 2014 and failing to tell them about it until yesterday. They also called on boss Marissa Mayer to quit.

News of the security lapse could also damage Yahoo as it tries to sell its digital operations to Verizon Communications for £3.7 billion.

Yahoo said the attack was committed by a “state-sponsored actor”. A spokesman added: “Yahoo is working closely with law enforcement on this matter.”