Friday’s unprecedented ransomware attack may have stopped spreading to new machines — at least briefly — thanks to a “kill switch” that a security researcher has activated.

The ransomware, called Wana Decryptor or WannaCry, has been found infecting machines across the globe. It works by exploiting a Windows vulnerability that the U.S. National Security Agency may have used for spying.

The malware encrypts data on a PC and shows users a note demanding $ 300 in bitcoin to have their data decrypted. Images of the ransom note have been circulating on Twitter. Security experts have detected tens of thousands of attacks, apparently spreading over LANs and the internet like a computer worm.

To read this article in full or to leave a comment, please click here