Digital Realty was reportedly one of the victims of Chinese hacking group Salt Typhoon.

Security agencies in the US have apparently identified the data center operator as one of the companies breached by the cybercrime gang.

The hackers are said to have used vulnerabilities in Cisco networking equipment to mount a multi-year cybercrime campaign that saw the group breach US telecoms infrastructure and intercept confidential information, as well as reportedly being able to listen in on phone calls in real time. It is thought to have targeted communications from government agencies.

US senator Mark R. Warner, vice chair of the upper house’s intelligence committee, described the incident as the “worst telecom hack in our nation’s history.”

Now National Security Agency insiders speaking to NextGov say investigations have shown that Digital Realty was one of the victims, along with media firm Comcast.

The sources, who spoke on condition of anonymity, did not disclose which parts of DLR’s infrastructure were compromised, or if data was stolen. Digital Realty has more than 115 data centers in North and South America, and 300 in total globally.

T-Mobile, AT&T, Verizon, and Lumen Technologies were all reportedly attacked by Salt Typhoon during the campaign.

DCD has contacted Digital Realty for comment on the report.