"There was a possibility of unauthorized access by exploiting the vulnerability of network equipment," the spokesperson at Japan Aerospace Exploration Agency (JAXA) said, declining to elaborate on details such as when the attack took place, Reuters reported.
The space agency learned of the possibility of the unauthorized access after receiving information from an external organization and conducting an internal investigation, the spokesperson said, declining to identify the organization's name.
The investigation is ongoing, the spokesperson said.
Japanese media reported Wednesday that the cyberattack occurred during the summer and the police became aware of the attack and notified JAXA this autumn. The Yomiuri newspaper first reported the incident.