Russian hackers were able to access an unclassified Pentagon computer network earlier this year, US Secretary of Defense Ashton Carter said Thursday.
"We quickly identified the compromise and had a team of incident responders hunting down the intruders within 24 hours," Carter said during a speech on technology and cybersecurity at Stanford University in California.
"Earlier this year, the sensors that guard DoD's unclassified networks detected Russian hackers accessing one of our networks," Carter said, using an acronym for the Department of Defense.
The Pentagon analysed the "network activity, associated it with Russia, and then quickly kicked them off the network," he said.
National Security Agency chief Michael Rogers said in March that Russia was pushing for a show of force in the realm of cybersecurity as it flexed its muscles in Crimea and eastern Ukraine.
"I'm seeing a much more active Russia in the cyber arena in a much more visible way," he told a congressional hearing.
Carter was in Silicon Valley on Thursday on a two-day trip meant to strengthen Pentagon ties with the high-tech sector.