An “accidental hero” has halted the global spread of the WannaCry ransomware, reportedly by spending a few dollars on registering a domain name hidden in the malware. The ransomware has wreaked havoc on organizations including FedEx and Telefonica, as well as the UK’s National Health Service (NHS), where operations were cancelled, x-rays, test results and patient records became unavailable and phones did not work.

However, a UK cybersecurity researcher tweeting as @malwaretechblog, with the help of Darien Huss from security firm Proofpoint, found and activated a “kill switch” in the malicious software. The switch was hardcoded into the malware in case the creator wanted to stop it spreading. This involved a very long nonsensical domain name that the malware makes a request to – just as if it was looking up any website – and if the request comes back and shows that the domain is live, the kill switch takes effect and the malware stops spreading. READ MORE