Symantec researchers have found multiple instances of code used both in the North Korea-linked group's previous activity and in early versions of WannaCry

Symantec says 'highly likely' North Korea group behind ransomware attacks

Cyber security researchers have found technical evidence to link North Korea with the global WannaCry "ransomware" cyber attack

North Korea's Unit 180, the cyber warfare cell worries the West

Researchers scattered across the globe collaborated to develop a workaround to unlock the encryption key for files hit in the global attack

French researchers find way to unlock WannaCry without ransom

Stocks of cyber security firms rise as the global scale of WannaCry becomes apparent