T-Mobile said a cyberattack earlier this month that exposed millions of customer records was carried out using specialized tools to gain entry to the network, followed by brute force-style hacking techniques to access user data. From a report: “In short, this individual’s intent was to break in and steal data, and they succeeded,” Chief Executive Officer Mike Sievert said Friday in a statement, the company’s fullest account yet of what happened. The company has hired cybersecurity provider Mandiant and consulting firm KPMG to improve its defenses, he said. The breach, the fourth that has compromised T-Mobile customer records in as many years, involved personal information including names, dates of birth, Social Security numbers and driver’s license information. Sievert said the company is working with law enforcement and can’t share further details of what happened. Further reading: T-Mobile Hacker Explains How He Breached Carrier’s Security.