And security experts fear they could be targeting the Winter Games, to be held in the neighbouring South in February.
The host city Pyeongchang is just 50 miles from the region’s demilitarised zone which divides the two rival nations.
US tech expert Priscilla Moriuchi warned that tyrant Kim wants use his hacker army to spark “chaos” in South Korea.
She told the Telegraph: “There is definitely a strong thread throughout these attacks of a North Korean connection through the malware and, it seems, through the techniques that they’re using.
“That desire to target South Korea and create chaos that would undermine South Korea’s image is still very much a goal for North Korea.
“It’s more likely that they would do something in the cyber operations sphere.”
Patrick Cronin, of the Washington-based think-tank Centre for a New American Security, added: “The Olympics would be a prime opportunity for cyber espionage and sabotage by North Korea.”
North Korea was yesterday blamed for the WannaCry malware attack that targeted the NHS earlier this year.
The attack hit more than 300,000 computers in 150 countries, causing billions of pounds worth of damage.
Dozens of NHS trusts were caught up in the security breach, which proved highly embarrassing for the health service.
Screens were frozen with a warning they would not be unlocked unless a ransom was paid.
Foreign Office minister Lord Ahmad said: “We condemn these actions and commit ourselves to working with all responsible states to combat destructive criminal use of cyber space.
“The indiscriminate use of the WannaCry ransomware demonstrates North Korean actors using their cyber programme to circumvent sanctions.”
Kim’s hackers are believed to have stolen up to £5million in Bitcoin, a popular digital currency, to raise cash for the rogue state.
Pyongyang has turned to Bitcoin to circumvent the crippling economic sanctions placed on the war-hungry dictatorship by the UN.
Cristiana Brafman Kittner, of cyber-security firm FireEye, said hackers linked to North Korea had targeted “multiple Bitcoin exchanges” this year.
She warned: “We believe that some of the criminal activity we are observing originating from North Korea is a result of the regime looking for alternative sources of revenue.
“North Korean cyber threat actors present an immediate risk to the financial services sector worldwide.”