The Tokyo 2020 Olympic Games suffered almost half a billion cyberattacks from multiple state-sponsored hackers. NTT, who provided the Games with various telecommunication and cybersecurity services, successfully blocked the attempts, so no impact was felt during the competition.
https://www.notebookcheck.net/450-million-cyberattacks-were-attempted-on-the-Tokyo-2020-Olympic-Games-infrastructure.574937.0.html