WASHINGTON, June 14 (Reuters) - Russian government hackers penetrated the computer network of the Democratic National Committee and gained access to all opposition research on Republican presidential candidate Donald Trump, the committee and security researchers said on Tuesday.
Representative Debbie Wasserman Schultz, chairwoman of the Democratic National Committee, confirmed the breach to Reuters, first reported by the Washington Post.
"When we discovered the intrusion, we treated this like the serious incident it is ...," Wasserman Schultz said in a statement. "Our team moved as quickly as possible to kick out the intruders and secure our network."
The Washington Post quoted U.S. officials as saying Russian spies also targeted the networks of Trump and Democratic presidential candidate Hillary Clinton, as well as computers of some Republican political action committees.
The intrusion is emblematic of the sophistication of Russian hackers, who intelligence officials have long viewed as the most talented of U.S. adversaries in cyberspace.
In Moscow, a Kremlin spokesman did not immediately respond to a request for comment.
Two separate groups were able to enter the DNC's system and read email and chat communications, according to the committee and CrowdStrike, the cyber firm that helped clean up the breach.
BEARS ON THE LOOSE
CrowdStrike began assisting the DNC in May and identified two groups, said Dmitri Alperovitch, the company's co-founder and chief technology officer. Both were kicked out this weekend, he said.
The first, which CrowdStrike named Cozy Bear, entered the DNC's systems last summer, according to the firm. It primarily monitored email and chat conversations and may be working for Russia's Federal Security Service, or FSB, Alperovitch said.
FSB was once run by Russian President Vladimir Putin.
The second group, nicknamed Fancy Bear, is probably working on behalf of Russia's military, Alperovitch said. It gained entry in late April and "went straight to the oppo research specifically on Donald Trump and exfiltrated some of it," he said.
Alperovitch added that both groups were among "the best threat actors that we've ever encountered" but that they appeared to not be working together.
Cyber attacks against political candidates and organizations are common worldwide. U.S. National Intelligence Director James Clapper said last month he was aware of attempted hacks on campaigns and related organizations and that he expected to see more as the November presidential election nears.
The last two U.S. presidential cycles in 2008 and 2012 witnessed a barrage of cyber attacks from a range of adversaries targeting President Barack Obama's campaign and the campaigns of his Republican foes.
U.S. intelligence officials have said many previous assaults were linked to Chinese hackers.
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(Reporting by Susan Heavey; Writing by Mohammad Zargham; Editing by James Dalgleish)