TalkTalk cyber-attack: company has received 'ransom demand'

Company confirms contact from someone claiming responsibility for attack that potentially compromised customers' personal data

TalkTalk says it has received a ransom demand from an individual or group claiming responsibility for a cyber-attack that has potentially compromised the credit card and bank details of millions of customers.

The telecommunications and media firm has said it does not know how many of its 4 million customers have been affected by what it called a "significant and sustained" attack on its systems.