The high-profile cyberattack on Sony would have challenged almost any cyber security measures, the Federal Bureau of Investigation has said. An FBI investigation calls the level of sophistication of the software used by the hackers “extremely high” and the attacks “organized and certainly persistent.”

Joe Demarest, assistant director of the FBI’s cyber division, told the Senate Banking Committee that “the malware that was used would have gotten past 90 percent of the Net defenses that are out there today in private industry and [would have been] likely to challenge even state government.” His comments were officially confirmed later by the FBI.