Cellcom hit by major cyber attack, disrupting voice and text services

Wisconsin telecommunications provider Cellcom said it recently experienced a significant cyber attack that disrupted both voice and text services.

 

In a data security incident notice published on its website, Cellcom said that on May 14, it detected unusual activity within its internal network. The company immediately launched an investigation, with assistance from external cyber security experts, to determine the nature and scope of the incident.

 

As a precautionary measure, Cellcom had to take its network offline, resulting in disruptions to both voice and text services for its customers.

 

“We informed the FBI and state officials and enlisted the assistance of experts in this field. We began working on an investigation into how the incident occurred and at the same time implemented our restoration plan to get voice and SMS services back as quickly as possible,” Cellcom said.

 

In a letter sent to its customers, Brighid Riordan, CEO of Cellcom, said that sensitive personal information including names, addressees, and financial information were not compromised by the incident.

 

“The incident was concentrated on an area of our network separate from where we store sensitive information related to customers. While it will be some time before we have the certainty we would like, at this time, we have a high degree of confidence that information related to you was not involved in this event,” reads the FAQ section.

 

Riordan added that the company is working tirelessly to restore its services. While customers can still send SMS and make calls to other Cellcom users, calls to users on other mobile networks will be available again shortly.

 

At the time of publishing, no known hacker group claimed responsibility for the cyber attack on Cellcom. The telecom provider also did not share details on who was behind the attack, how much data was compromised, or whether it has received a ransom demand.