Ransomware Attack Halted By Accidental Hero: Warns It Isn’t Over

However the spread of this attack which has now been traced to a group of North Korean Hackers was halted quite suddenly when a UK cybersecurity researcher who tweeted as @malwaretechblog, with assistance from Darien Huff from Proofpoint, a security firm, discovered and activated a "kill switch" inadvertently that was inside of the malicious software.

The 22-year-old researcher from southwest England, who only identified himself as MalwareTech, works for a threat intelligence company based in LA called Kryptos Logic.

He told the Guardian that he was out having lunch with one of his friends and returned at around 3 pm and noticed all of the news articles coming out about the NHS and different UK organisations that were being hit.