Reuters reports the Clinton campaign was also the subject of a hack by a foreign government:

The computer network used by Democratic presidential candidate Hillary Clinton’s campaign was hacked as part of a broad cyber attack on Democratic political organizations, people familiar with the matter told Reuters…

The involvement of the Justice Department’s national security division is a sign that the Obama administration has concluded that the hacking was state sponsored, individuals with knowledge of the investigation said.

The Reuters reports follows previous stories including this one at the Washington Post which indicated the Clinton camp had been warned about a possible hack. However that story said there was no evidence the hack had been successful. Thursday night, Yahoo News published a story revealing more details about the FBI warning to the Clinton camp:

The FBI warned the Clinton campaign that it was a target of a cyberattack last March, just weeks before the Democratic National Committee discovered it had been penetrated by hackers it now believes were working for Russian intelligence, two sources who have been briefed on the matter told Yahoo News.

In a meeting with senior officials at the campaign’s Brooklyn headquarters, FBI agents laid out concerns that cyberhackers had used so-called spear-phishing emails as part of an attempt to penetrate the campaign’s computers, the sources said. One of the sources said agents conducting a national security investigation asked the Clinton campaign to turn over internal computer logs as well as the personal email addresses of senior campaign officials. But the campaign, through its lawyers, declined to provide the data, deciding that the FBI’s request for sensitive personal and campaign information data was too broad and intrusive, the source said.

It’s interesting that the Clinton campaign refused to turn over information to the FBI. One possible reason beyond the one they gave: It might take the decision whether to say anything about the hack out of their hands.

At the time the FBI issued the warning to the campaign it did not identify a possible source of the attack. However, there has been mounting evidence Russia was behind the DNC hack which took place at the same time. This week a group called ThreatConnect revealed evidence that Guccifer 2.0, a person claiming to be the DNC hacker, is likely a fictitious character created as part of a Russian propaganda effort. The FBI also announced it was looking into the DNC earlier this week.

Though Wikileaks has not revealed the source of the DNC emails and phone messages it has released, founder Julian Assange has suggested he has more (and more damaging) information yet to come. A number of stories published this week have suggested Democrats are nervous about what may be in the next leak.