T-Mobile data breach sees phone numbers and call records leaked online

Renovated Headquarters
(Image credit: T-Mobile)

T-Mobile has revealed that it suffered a data breach in which customers' proprietary network information (CPNI), including their phone numbers and call records, was exposed online.

Earlier this week, the US telecom began informing its customers via text message that a security incident had occurred that may have impacted some of their account information. 

However, T-Mobile provided further details in a notice of security incident on its website and explained that its security team recently discovered “malicious, unauthorized access” to its systems.

Following this discovery, an investigation was launched with assistance from leading cybersecurity forensic experts to determine what happened and exactly what customer information was exposed.

Customer proprietary network information

According to T-Mobile, the CPNI accessed by hackers may have included customers' phone numbers, the number of lines on their accounts and in some cases, call-related information.

Thankfully though, the data accessed did not include customers' names, addresses, email addresses, financial data, credit card information, social security numbers, tax IDs, passwords or PINs.

Affected customers have already received text messages from T-Mobile informing them of the situation but they should remain on the lookout for any suspicious texts claiming to be from the company or messages containing links to third-party websites as cybercriminals often use the news of a data breach or security incident to launch phishing attacks to try and steal user credentials.

Although T-Mobile has suffered another data breach, this attack appears to be less severe than the one that occurred in March in which hackers were able to gain access to both customer and employee data.

Via BleepingComputer

Anthony Spadafora

After working with the TechRadar Pro team for the last several years, Anthony is now the security and networking editor at Tom’s Guide where he covers everything from data breaches and ransomware gangs to the best way to cover your whole home or business with Wi-Fi. When not writing, you can find him tinkering with PCs and game consoles, managing cables and upgrading his smart home.