Dixons Carphone has revealed it has been hit by a huge data breach.
The high-street retailer has admitted that over a million personal data records of its customers have been accessed by hackers, with 5.9 million payment cards also affected.
The company says it has informed the ICO and the police of the attack.
The breach was uncovered by Dixons Carphone this week, but apparently took place back in July 2017, when hackers tried to access a processing system used by its Currys PC World and Dixons Travel stores.
The successful hack saw "an attempt to compromise" 5.8 million credit and debit cards, but only 105,000 cards that lacked chip-and-pin protection were leaked, the company said.
However the hackers were able to access the personal data records of 1.2 million customers, with details such as names, addresses and email addresses all leaked.
Dixons Carphone says it is now contacting all affected customers to offer advise, and was also toughening up its cybersecurity.
“We are extremely disappointed and sorry for any upset this may cause. The protection of our data has to be at the heart of our business, and we’ve fallen short here," Dixons Carphone chief executive Alex Baldock said in a statement.
"We are determined to put this right and are taking steps to do so; we promptly launched an investigation, engaged leading cyber security experts, added extra security measures to our systems and will be communicating directly with those affected."
"Cyber crime is a continual battle for business today and we are determined to tackle this fast-changing challenge.”
- Looking to boost your security? Here's the best antivirus of 2018