UK giant TalkTalk has confirmed it is investigating a data breach after a hacker claimed to have stolen the personal information of millions of customers.
In a post on a popular cybercrime forum seen by TechCrunch, an individual using the alias “B0ND” claimed to have stolen the personal data of over 18.8 million current and former TalkTalk subscribers. This data, which the threat actor offers for sale, supposedly includes customer names, email addresses, IP addresses, phone numbers, and subscriber pins.
In a statement to TechCrunch, TalkTalk spokesperson Liz Holloway confirmed that the company is investigating the data breach, but said the 18.8 million figure claimed by the hacker is “completely inaccurate and grossly excessive.”
TechCrunch understands that TalkTalk currently has around 2.4 million customers.
“As part of our regular security monitoring, given our continued focus on protecting customers’ personal data, we have been made aware of unexpected access to our third-party vendors’ systems,” Holloway told TechCrunch. “Our security incident response team continues to work with the supplier regarding this matter and preventive containment steps immediately.”
Holloway declined to name the third-party vendor, but screenshots shared by B0ND suggest the data was stolen from CSG’s Ascendon platform, which TalkTalk uses to manage subscriptions.
CSG did not immediately respond to TechCrunch’s questions.
TechCrunch understands that the personal details of a small subset of TalkTalk customers are stored in Ascendon. Holloway confirmed to TechCrunch that “no financial or financial information is stored on this system.”
TalkTalk was previously fined £400,000 following a 2015 data breach in which hackers stole the personal data of 157,000 customers, including some financial information. The UK Information Commissioner said at the time that TalkTalk had failed to implement “the most basic cybersecurity measures”, allowing hackers to “easily penetrate its systems”.
