The Pentagon identified the breach on Oct. 4 and is still investigating.

In cybersecurity probes of Pentagon weapon systems in recent years, pen-testers were able to wrest control of systems with relative ease, according to GAO.

CIO Dana Deasy lays out the department's plan in response to Sen. Ron Wyden, who raised concerna about the security of DOD's many public-facing sites.

"I think that line has to be drawn, and we have to respond, and they need to pay a fairly significant price for what they're doing.”

A Chinese intelligence agency was able to successfully hack into a Navy contractor around February, stealing more than a half terabyte worth of highly sensitive documents.

The highest bounty was $5,000 paid out eight times.