A 15-year-old boy has been arrested in connection with a hack that put the 4 million customers of British telecommunications company TalkTalk at risk, the Guardian reports. British police arrested the teen on suspicion of violating the Computer Misuse Act Monday in Northern Ireland and searched his home, according to the New York Times. On Tuesday, he was released on bail. “We know this has been a worrying time for customers, and we are grateful for the swift response and hard work of the police," the Guardian quotes a TalkTalk company statement. It has been the only arrest so far in the cyberattack first reported last week.
TalkTalk says a group of hackers demanded ransom in connection with the cyberattack, though multiple groups are claiming responsibility for it, the Times reports. According to the Guardian, when TalkTalk announced the data breach last Wednesday it feared hackers may have gotten bank and personal information from its phone and Internet customers. But the company now believes the hack was less serious than initially feared, and no credit or debit card numbers were stolen, the BBC reports. In the days since the hack—TalkTalk's third data breach in the past 10 months—stocks have tumbled and the government has promised an investigation into the company's cybersecurity, the Times reports.