The list of those hacked in recent years includes law firms, think tanks, news organizations, human rights groups, contractors, congressional offices, embassies and federal agencies.
The information compromised by such intrusions, security experts say, would be enough to map how power is exercised in Washington to a remarkably nuanced degree. The only question, they say, is whether the Chinese have the analytical resources to sort through the massive troves of data they steal every day.
“The dark secret is there is no such thing as a secure unclassified network,” said James A. Lewis, a cybersecurity expert at the Center for Strategic and International Studies, which has been hacked in the past. “Law firms, think tanks, newspapers — if there’s something of interest, you should assume you’ve been penetrated.”