O2 customer data grab: Not-a-hack creds for sale on dark web

Hackers have gained access to customer data on UK telco O2 – and put it up for sale on the dark web.

The compromised data was likely obtained by using usernames and passwords stolen from gaming website XSplit three years ago in order to log onto O2 accounts.

When the login details matched, the hackers could access O2 customer data through a process known as "credential stuffing".

Password reuse fertilised dark web harvest

Hackers harvested all manner of sensitive data including dates of birth, phone numbers, emails, and passwords from O2 using the tactic, which ultimately relies on password reuse. The same password re-use problem exposes victims to attack on other third-party websites.

O2 – which stresses that it has not suffered a breach itself – has reported the case to police.

We have not suffered a data breach. Credential stuffing is a challenge for businesses and can result in many company’s customer data being sold on the dark net. We have reported all the details passed to us about the seller to law enforcement and we continue to help with their investigations.

We act immediately if we are given evidence of personal credentials being taken from the Internet and used to try and compromise a customer’s account. We take fraud and security seriously and if we believe a customer is at risk from fraud we inform them so they can take steps to protect themselves.

The incident underlines the dangers of password reuse, particularly among consumers.

Jon Geater, CTO, Thales e-Security, commented: "In today’s big-data fuelled world, with records such as usernames and passwords – which consumers often don’t change between websites – and email addresses, birthdates and phone-numbers also stolen – which consumers can't change – this type of simple breach is a goldmine for hackers.”

James Romer, chief security architect Europe, SecureAuth, added: “We all know that using the same password/username credentials across multiple sites is bad idea, yet it still happens far too often. Users have difficulty remembering different passwords for the multitude of needs of our online lives, so they default to using the same password over and over and it’s generally something simple. How many times has 1234 topped the most common password list?”

“However, bad actors are taking advantage of this laissez faire attitude, trying stolen credentials not just on one site but a number, even employing botnet which automate the process. Where the same credential combinations are repeatedly being used across a number of accounts, it’s the equivalent of a skeleton key to your online life,” Romer warned. ®