Shares of T-Mobile (NASDAQ:TMUS) are continuing lower in Friday’s pre-market session after the company disclosed a cybersecurity accident late last night.
The wireless network operator said it “identified that a bad actor was obtaining data through a single Application Programming Interface (“API”) without authorization” and was “able to trace the source of the malicious activity and stop it.”
According to the company, the “most sensitive types of customer information” were not accessed, although the attack did expose “name, billing address, email, phone number, date of birth, T-Mobile account number and information such as the number of lines on the account and plan features.”
T-Mobile says “malicious activity appears to be fully contained at this time”, but reports that data of “approximately 37 million current postpaid and prepaid customer accounts” may have been compromised.
The company added it “may incur significant expenses in connection with this incident,” although no further details were provided at this time.
Shares of TMUS are slipping around 2% in response to the incident.