China reportedly had ‘deep, persistent access’ to Japanese networks for months

Cybersecurity breach in Japan's defense networks by hackers from China.

Key points:

1. Hackers from China had "deep, persistent access" to Japanese defense networks.
2. The breach was discovered by the National Security Agency in late 2020 and persisted through the end of the Trump administration and early 2021.
3. Japan initially declined assistance from US Cyber Command and opted for domestic commercial security firms, but later adopted a more active national security strategy, including the establishment of a new cyber command and the addition of 4,000 cybersecurity personnel.