Japan will develop its first-ever computer virus by next March as a defense measure against cyberattacks, sources familiar with the matter said Monday.

The Defense Ministry is considering malware that can break into an opponent's computer system, hoping such a computer virus will work as deterrence against cyberattacks, the sources said.

The government has said it is looking to enhance its defense capabilities beyond ground, marine and air domains to address security challenges in new domains such as cyberspace and outer space amid technological advances in recent years.


Japan lags behind other countries in addressing the threat of cyberattacks. It plans to increase the number of personnel in its cyberspace unit to 220 from 150, compared with 6,200 in the United States, 7,000 in North Korea and 130,000 in China, according to the ministry.

The ministry has been considering specific measures against cyberattacks since it pledged to bolster its cyberspace defense under its latest national defense guidelines launched last December.

Some defense experts say it could exceed the limits of the country's exclusively defense-oriented policy, if the ministry possesses the ability to obstruct an enemy's use of cyberspace.

The virus to be developed by private companies will be used only for defense purpose, not for pre-emptive attack, a ministry source said. The government allows cyberattacks only against a country or an organization equivalent to a country.