The US charged a North Korean programmer Thursday with some of the most dramatic global hacking cases of recent years, alleging they were carried out on behalf of the regime in Pyongyang.
The hacks included the WannaCry 2.0 virus, the 2104 Sony Pictures attack, and the 2016 cyber-heist of Bangladesh's central bank.
The US Justice and Treasury Departments said Park Jin Hyok was "part of the conspiracy" that masterminded those notorious hacks "on behalf of the Government of North Korea or the Workers' Party of Korea."
The Justice Department unveiled criminal charges related to the hacking against Park.
The Treasury announced financial sanctions on Park and a government-controlled company he worked for, Chosun Expo Joint Venture.
"North Korea has demonstrated a pattern of disruptive and harmful cyber activity that is inconsistent with the growing consensus on what constitutes responsible state behavior in cyberspace," the Treasury said in a statement.
"Our policy is to hold North Korea accountable and demonstrate to the regime that there is a cost to its provocative and irresponsible actions.
The move came as Washington seeks to get traction in negotiations with Pyongyang over halting its nuclear weapons program.
After an impasse of several weeks, earlier Thursday President Donald Trump indicated in a tweet that talks were moving forward.
"Kim Jong Un of North Korea proclaims 'unwavering faith in President Trump.' Thank you to Chairman Kim. We will get it done together!" Trump exclaimed on Twitter.
The charges and sanctions singled out Park in some of the most notorious and damaging hacks in recent years, which had already been unofficially pinned on North Korea.
The cyber-theft of a huge amount of files from Sony Pictures Entertainment in 2014 saw the company lose control of private communications between top executives, personal data of thousands of employees and customers, and scripts and information on upcoming films.
Leaked emails from the hack showed company chiefs giving unvarnished opinions on some of Hollywood's top stars and resulted in the departure of at least one official.
The hack of the central bank of Bangladesh saw at least $81 million stolen and transferred between a number of accounts in the Philippines and elsewhere, rendering most of it unrecoverable.
WannaCry 2.0 was ransomware which spread virulently around the world in May 2017, infecting some 300,000 computers in 150 countries.
It encrypted user files and offered to free them in exchange for hundreds of dollars each.
Last December the North Korean government called allegations that it was behind the ransomware "absurd" and a "grave political provocation."