29 May, 2017
Mr Hutchins, who works for Los Angeles-based Kryptos Logic, said he fights malware because "it's the right thing to do", and said hundreds of computer experts worked throughout the weekend to combat the global virus.
"I woke up at around 10 AM and checked onto the United Kingdom cyber threat sharing platform where I had been following the spread of the Emotet banking malware, something which seemed incredibly significant until today", he said.
"I was just sort of doing my job and I don't really think that I'm a hero at all".
In the first hours after the virus struck Friday, the computer whiz and surfing enthusiast who lives with his family in a small seaside town in southwest England discovered a so-called "kill switch" that slowed the unprecedented outbreak.
In a letter to The Times, Sir David said: "Should Microsoft have stopped supporting Windows XP so soon, knowing that institutions had invested heavily in it (at the urging of the company at the time)?"
WannaCry paralysed computers running mostly older versions of Microsoft Windows by encrypting users' computer files and displaying a message demanding anywhere from $US300 to $US600 to release them; failure to pay would leave the data mangled and likely beyond fix. He prevented more than 100,000 computers across the globe from being infected by registering a website domain name that unexpectedly stopped the spread of the ransomware, after he discovered that activating a specific web domain could disable the worm.
Salim Neino, chief executive of Kryptos Logic, said Mr Hutchins took over the "kill switch" on Friday afternoon European time, before it could fully affect the United States.
While he did not realize it yet, this simple act had "unknowingly killed the malware" with suggestions the domain had become a "kill switch" to prevent the virus spreading further. It was a very exciting moment.
But Marcus Hutchins doesn't consider himself a hero.
"I've still been working across from my company Kryptos Logic, we've been trying to provide the sort of, the IP addresses to NCSC (National Cyber Security Centre), the Federal Bureau of Investigation, so that victims can be notified", he said.
Hutchins is part of a global community of cyber guards who patrol the Internet for cybercrime and try to thwart it before anyone is victimized. It is not uncommon for members to use aliases, to protect from retaliatory attacks and ensure privacy.
Mr Hutchins has long tweeted under the handle MalwareTech, which features a profile photo of a pouty-faced cat wearing enormous sunglasses.
Already Monday some computer researchers were analyzing technical clues on the possible origin of WannaCry - and some clues pointed to North Korea.
'In future someone might want to retaliate - they could find my identity within seconds, ' he told Mail Online. "We are continuing to investigate for stronger connections".
The keen surfer, who reportedly lives in Devon, was praised by the National Cyber Security Centre (NCSC) for his part in tackling the ransomware's propagation around the world.
MalwareTech said he had also been providing the NCSC with data to help notify infected companies, warning that computers which had not had their security brought up to date will be vulnerable to further attack.
The news agency said there have been no reported incidents of the ransomware affecting government agencies. It was not clear whether the files had been recovered.
