The Pentagon is revealing that it suffered one of its largest-ever losses of sensitive defense data this spring to a cyber attack that it blames on an unspecified foreign government.
The loss is an example of why the Pentagon has developed new cyber security rules that emphasize deeper defenses, more collaboration with private industry and new steps to stop thefts by malicious insiders.
William Lynn, the deputy secretary of defense, said in a speech outlining the new strategy that 24,000 files were stolen from a defense industry computer network in a single intrusion in March. He offered no details.
In an interview, Lynn said the Pentagon has a good idea who made the attack but he would not offer details. He said it was by a nation rather an individual.