Home security company ADT announced Tuesday that it experienced a massive security breach.

According to a filing with the Securities and Exchange Commission, unknown cybercriminals accessed the information of thousands of ADT customers. The information includes home addresses and phone numbers.

“After becoming aware of the incident, the company promptly took steps to shut down the unauthorized access and launched an investigation, partnering with leading third-party cybersecurity industry experts,” the SEC filing reads. “The company is continuing its investigation into this cybersecurity incident and has notified the customers it believes to have been affected, who comprise a small percentage of the company’s overall subscriber base.”

The filing also states there is no reason to believe that the hackers gained access to sensitive financial information or that the attack compromised any specific ADT security system. ADT didn’t confirm when the hack took place.

ADT, which once stood for American District Telegraph, is one of the most popular home security companies in the U.S., boasting 6 million customers.

While cyberattacks at home security firms are uncommon, companies like Ring and SimpliSafe have experienced similar attacks in the past few years.

• Vaughn Cockayne can be reached at vcockayne@washingtontimes.com.