U.S. investigators believe that Chinese state-sponsored threat actors are responsible for breaching computer networks linked to the FBI that hold information related to domestic surveillance orders, The Wall Street Journal reported on March 6.

News outlets including CNN and AP reported on March 5 that the FBI was investigating "suspicious activity" that was first discovered on Feb. 17, but there was no indication of a perpetrator at that point. The threat actors reportedly gained access to information about the calls and internet activity of criminal suspects and other individuals under government surveillance warrants and wiretaps, including incoming and outgoing calls, IP and website addresses, and some routing information, though not the specific contents of calls or digital communication. The White House, Department of Homeland Security and National Security Agency are also involved in the investigation, which is in its early stages, and the scope and the severity of the intrusion are still unknown.