Russian hackers struck across US politics

The Russian hackers who hit the Democratic National Committee and Hillary Clinton's campaign burrowed much further into the US political system, sweeping in law firms, lobbyists, consultants, foundations and the policy groups known as think tanks, according to a person familiar with investigations of the attacks.

Almost 4,000 Google accounts were targeted in an elaborate "spear phishing" campaign - intended to trick users into providing access so that information could be gleaned from personal and organizational accounts - from October through mid-May, according to the person, who asked not to be identified discussing confidential information.

The sweeping scope of the spying on the US political establishment suggests an information dragnet far larger than previously reported and one meant to gather a near-encyclopaedic understanding of the next president and those who will influence his or her thinking. Based on data now being analysed, various security researchers believe the campaign stems from hackers linked to Russian intelligence services and has been broadly successful, extracting reams of reports, policy papers, correspondence and other information.

Among the policy groups targeted was the Center for American Progress, which has ties to Clinton and the Obama administration. "We are constantly reviewing our security and operations to prevent and thwart unauthorised activity," Liz Bartolomeo, a spokeswoman for the center, said in an e-mailed statement. "We have reviewed our systems and we believe our security measures have prevented unwanted access to our systems."

"These foreign governments are negotiating machines" with much to gain from a US politician's priorities and weaknesses, said John Prisco, chief executive officer of Rockville, Maryland-based security company Triumfant.