A British cyber expert has told how he jumped around in excitement after discovering a kill switch which halts the global spread of the malicious software currently infecting the NHS and organisations in more than 100 countries.
The 22-year-old researcher has been hailed as an ‘accidental hero’ online.
The anonymous blogger discovered that upon infecting a new computer, the virus contacts a remote web address and only starts taking files hostage if it finds that address unreachable.
But if it can connect, the WannaCry program terminates itself – a function likely installed by its  creator as a failsafe in case the software became uncontrollable.
By discovering the web address was unregistered, and purchasing it for less than £10, the researcher who tweets from @MalwareTechBlog, was able to redirect 5,000 connections per seconds to a harmless “sinkhole” server.
In an update posted moments ago, he explained how at 6.30pm yesterday after experimentation, he learned that by …