LONDON — A 22-year-old computer researcher is being hailed a hero for stopping the global spread of a ransomware attack that began last Friday. <br /> <br />The ransomware known as “WannaCry” exploits a vulnerability in Microsoft Windows that was revealed in stolen NSA documents, Reuters reported. <br /> <br />The malicious software locks computers and demands users pay $300 in BitCoin to retrieve their files. <br /> <br />An anonymous British researcher tweeting as @MalwareTechBlog stopped the attack after discovering the malware was connecting to an unregistered domain, the Guardian reported. <br /> <br />The researcher works for LA-based intelligence firm, Kryptos Logic. <br /> <br />He paid around US$10 to register the domain name, which activated a kill switch in the ransomware. <br /> <br />However, the researcher warned that the hackers would change the code and reboot the ransomware. <br /> <br />Cybersecurity experts feared there would be a fresh bout of infections on Monday as people returned to work after the weekend. <br /> <br />Last week, the ransomware locked more than 200,000 computers in over 150 countries and caused chaos at organisations including Britain’s National Health Service, FedEx, and Telefonica in Spain. <br /> <br />Experts advised users to download a patch for Windows and reboot their computers to prevent the ransomware from spreading.
