"[We] continue to render technical assistance, rapidly share information to assist other potential victims, and work to strengthen cyber defenses across the commercial communications sector," the agencies stated. "We encourage any organization that believes it might be a victim to engage its local FBI Field Office or CISA."

TechCrunch notes that the breach is the latest in a series of sophisticated cyberattacks attributed to China-linked "Typhoon" hacking groups targeting critical US infrastructure. Experts warn that the campaign demonstrates heightened strategic targeting by PRC-affiliated actors, who increasingly focus on sensitive government and communications systems.