TalkTalk, a major UK telecom provider, is investigating a data breach involving the potential theft of personal information belonging to millions of its customers. The breach reportedly originated from a third-party supplier’s system and was discovered on January 21.

A hacker operating under the pseudonym “b0nd” claims to have obtained data from over 18.8 million current and former TalkTalk subscribers. The stolen information allegedly includes customer names, email addresses, IP addresses, phone numbers, and subscriber PINs. However, TalkTalk has stated that this figure is exaggerated, as the company currently has around 2.4 million customers.

The breach was linked to CSG’s Ascendon platform, which TalkTalk uses for subscription management. According to a statement sent to TechCrunch, CSG spokesperson Kristine Østergaard said the company learned that an unauthorized party accessed a provider’s data stored on the platform. While CSG denies its systems were directly compromised or responsible for the breach, TalkTalk confirmed that only a limited subset of customer details was affected and emphasized that no financial or billing information was exposed.

TalkTalk has activated its Security Incident Response team to investigate the incident and has implemented protective measures. The company is also working with its third-party supplier to address the issue and ensure containment.

This is not TalkTalk’s first data security incident. In 2015, the company faced a significant breach that exposed the sensitive information of 157,000 customers, leading to a £400,000 fine for inadequate cybersecurity measures. Similarly, at the beginning of the year, the second largest wireless carrier in the US, T-Mobile, faced another lawsuit over its handling of a 2021 data breach that revealed the personal data of more than 79 million customers.

The latest breach highlights the ongoing risks associated with data stored on external platforms and emphasizes the importance of stringent security protocols to safeguard customer information. As investigations continue, affected customers are urged to monitor their accounts for suspicious activity and follow best practices related to password management to enhance security.