Department of Defense Deputy Secretary William Lynn said that 24,000 files were taken in March from military contractor systems. That data leakage is increasingly common in the military complex. The good news? The DoD has a plan to fix its defenses.

Lynn didn’t provide further details on the attack or the contractor. On Thursday, the DoD released its strategy for operating in cyberspace.

The strategy boils down to:

Treat cyberspace as a domain to organize, train and equip the military. Deploy new defense operating concepts to protect military systems. Partner with government departments and the private sector. Work with allies to boost security. Leverage U.S. technical prowess and innovation.

Lynn, who also spoke broadly about cybersecurity and cooperation with the Department of Homeland Security, noted that intrusions are relatively common and that stolen data ranges from the mundane to Joint Strike Fighter designs.