T-Mobile acknowledges it was part of recent data breaches

T-Mobile was one of the telecom operators that was recently attacked by Chinese state-sponsored hackers in a cyber espionage operation.

According to The Wall Street Journal, the internet service provider confirms it was one the victims of a Chinese hacking group that was able to breach the company’s corporate network and spy on cellphone communications of so-called high-value targets.

Yet, it remains unclear what information was stolen and how many customers are affected by the breach.

“T-Mobile is closely monitoring this industry-wide attack, and at this time, T-Mobile systems and data have not been impacted in any significant way, and we have no evidence of impacts to customer information,” a T-Mobile spokeswoman says in a statement to The Wall Street Journal, adding that the company will monitor the situation closely with industry peers and relevant authorities.

At the end of October, the FBI and United States Cybersecurity & Infrastructure Security Agency (CISA) disclosed that they are investigating multiple unauthorized breaches to telecom operators in the US. Verizon, AT&T and Lumen Technologies are being named as potential targets, but that hasn’t been officially confirmed.

These attacks were allegedly carried out by members of the Chinese hacking group called Salt Typhoon, which is also known as Ghost Emperor, Earth Estries, FamousSparrow, and UNC2286.

Supposedly, the group used sophisticated methods to infiltrate American telecom companies through vulnerabilities in Cisco Systems routers. According to The Wall Street Journal, the first unauthorized access attempt happened over eight months ago.

“The hackers appear to have engaged in a vast collection of internet traffic from internet service providers that count businesses large and small, and millions of Americans, as their customers,” the newspaper wrote just before the FBI and CISA published their joint statement.

The amount and type of data that was exfiltrated is still under investigation, people familiar with the case told The Wall Street Journal. But possibly, the hackers were able to steal call logs, unencrypted texts and audio from targets.

Last week, the FBI and CISA confirmed that hackers from the People’s Republic of China (PRC) compromised confidential information of a limited number of government officials.

“Specifically, we have identified that PRC-affiliated actors have compromised networks at multiple telecommunications companies to enable the theft of customer call records data,” the intelligence agencies said in a joint statement.