Telecommunications giant Frontier Communications on Thursday informed the Securities and Exchange Commission (SEC) that certain systems were shut down following a cyberattack.
The incident, the company said in a regulatory filing with the SEC, was identified on April 14, when a third-party “gained unauthorized access to portions of its information technology environment”.
Frontier said it immediately initiated its incident response protocols and took steps to contain the incident, including shutting down certain systems, which “resulted in an operational disruption that could be considered material”.
According to Frontier, the attack was likely the work of a cybercrime group that gained access to various types of data, including personally identifiable information.
“As of the date of this filing, the company believes it has contained the incident and has restored its core information technology environment and is in the process of restoring normal business operations,” Frontier said.
The company also noted that it has notified law enforcement and that the incident will likely not have a material impact on its financial condition or results of operations.
While Frontier did not say what type of cyberattack it fell victim to, file-encrypting ransomware was likely involved, as shutting down systems is the typical response to ransomware.
The telecom giant also posted a notice on its website to inform visitors that it was experiencing “technical issues with our internal support systems”. Customers’ internet service has not been affected by the attack, but assistance is only being provided over the phone.
Based in Dallas, Texas, Frontier provides broadband internet, computer technical support, and digital television to residential and business customers across the US, as well as home phone services in some areas. It has a fiber-optic network at more than 5 million locations.
Related: CVS Group Restoring Systems Impacted by Cyberattack
Related: Lens Maker Hoya Scrambling to Restore Systems Following Cyberattack
Related: AT&T Data Breach Update: 51 Million Customers Impacted
