How 22-year-old computer geek stopped ransomware attack

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.

The ransomware known as “WannaCry” exploits a vulnerability in Microsoft Windows that was revealed in stolen NSA documents, Reuters reported.

The malicious software locks computers and demands users pay $300 in BitCoin to retrieve their files.

An anonymous British researcher tweeting as @MalwareTechBlog stopped the attack after discovering the malware was connecting to an unregistered domain, the Guardian reported.

The researcher works for LA-based intelligence firm, Kryptos Logic.

He paid around US$10 to register the domain name, which activated a kill switch in the ransomware.

However, the researcher warned that the hackers would change the code and reboot the ransomware.

Cybersecurity experts feared there would be a fresh bout of infections on Monday as people returned to work after the weekend.

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.

Experts advised users to download a patch for Windows and reboot their computers to prevent the ransomware from spreading.