Tokyo, Sept. 18 (Jiji Press)–Japan’s National Police Agency said Friday that a North Korean hacker group was behind a cyberattack spanning more than 100 countries, including Japan, that led to the theft of cryptocurrency worth about 1.7 billion yen.

The North Korean group, called WaterPlum, infected more than 30,000 devices with malware between December last year and July this year, stealing credentials for around 7,000 cryptocurrency accounts, according to a warning document released the same day.

Signed by seven organizations from four countries, including…