The US justice department has charged an alleged North Korean spy for helping to perpetrate cyber-attacks against the National Health Service that saw operations cancelled, ambulances diverted and patient records made unavailable following a worldwide hack in 2017 which affected computers in more than 150 countries.

Park Jin Hyok, 34, was also involved in an attack against the Sony Corporation in 2014 and an $81m theft from the Bank of Bangladesh in 2016, a criminal complaint released on Thursday claimed.

It was not immediately clear if North Korea, which authorities said the operative was working on behalf of during the WannaCry cyber-attack, would make Park available to US law enforcement authorities.

Park was thought to have operated from China, but prosecutors said they now believe he is in North Korea.

US officials believe the hackers struck in retribution for The Interview, a Hollywood spoof film that lampooned the isolated nation to such an extent that its state media warned it would wage “merciless retaliation”.

The 2017 attack – the largest to have ever hit the health service – hit computers at hospitals and GP surgeries across 48 NHS trusts.

At least 6,900 NHS appointments were cancelled, and up to 19,000 affected in total, after staff were forced to resort to using pen and paper when they were locked out of computerised systems.

A subsequent government report found that NHS trusts had been left vulnerable because basic cybersecurity recommendations were not followed. None of 88 out of 236 trusts assessed by NHS Digital before the attack were found to have satisfied the necessary cybersecurity standards.

It had been reported that nearly all NHS trusts were using an obsolete version of Windows for which Microsoft had stopped providing security updates three years previously, while it was also suggested that 90% of trusts were using Windows XP, then a 15-year-old system.

In the immediate aftermath of the hack the then-home secretary Amber Rudd was not able to confirm whether patient data had previously been backed up.

NHS workers at the time told the Guardian that the computers were affected after email attachments were opened, with the computers going down shortly after. Staff were swiftly told to “shut down, take out network cables and unplug the phones”, an NHS worker from an Essex hospital said.

The malware demanded ransoms of $300 (£230) in BitCoin to users on the infected computers. Although there was no evidence any NHS organisation paid, according to NAO, the financial cost of the crippling episode remains unclear.

The National Crime Agency’s director general of operations paid tribute to the collaboration between UK and US law enforcement and warned that the distinction between nation states and criminal groups in cases of cybercrime has become increasingly blurred.

“The ransomware attacks that affected the UK appear to be part of a series, and it’s right that they are prosecuted together to show the full scale of offending,” Steve Rodhouse said.

“The WannaCry attack highlighted that cybercrime affects not just the country’s prosperity and security, but also affects our everyday way of life.

“The distinction between nation states and criminal groups in terms of cybercrime is becoming frequently more blurred and today’s charges are a significant step forward in our investigation.”

Home Office minister Ben Wallace said in October 2017 that the government was “as sure as possible” that North Korea was responsible for the attack.

The US justice department confirmed that the WannaCry investigation – one of the most complex cybercriminal investigations it has ever conducted – is ongoing, and includes activity ranging through 2018.

The December 2014 cyber-attack against Sony’s film-making studio saw five of its upcoming movies, including the big-budget musical remake Annie, released online to file-sharing sites by a group calling itself Guardians of Peace.

Amid threats to moviegoers, Sony cancelled the theatrical release of The Interview and instead released it online.

Bloomberg reported that a Sony internal report linked the attack to a group associated with Pyongyang known as DarkSeoul, which wiped out the computers of South Korean banks and broadcasters in March 2013.

A North Korean official denied the country was responsible for cyber-attacks on Sony in an interview with Voice of America.

“Linking the DPRK to the Sony hacking is another fabrication targeting the country,” said the unidentified diplomat. “My country publicly declared that it would follow international norms banning hacking and piracy.”

A Sony spokeswoman declined to comment on Thursday.