David Sanger for the NYT:
Proving the source of a cyberattack is notoriously difficult. But researchers have concluded that the national committee was breached by two Russian intelligence agencies, which were the same attackers behind previous Russian cyberoperations at the White House, the State Department and the Joint Chiefs of Staff last year. And metadata from the released emails suggests that the documents passed through Russian computers. Though a hacker claimed responsibility for giving the emails to WikiLeaks, the same agencies are the prime suspects. Whether the thefts were ordered by Mr. Putin, or just carried out by apparatchiks who thought they might please him, is anyone’s guess….
It may take months, or years, to figure out the motives of those who stole the emails, and more important, whether they were being commanded by Russian authorities, and specifically by Mr. Putin. But the theft from the national committee would be among the most important state-sponsored hacks yet of an American organization, rivaled only by the attacks on the Office of Personnel Management by state-sponsored Chinese hackers, and the attack on Sony Pictures Entertainment, which Mr. Obama blamed on North Korea. There, too, embarrassing emails were released, but they had no political significance. The WikiLeaks release, however, has more of a tinge of Russian-style information war, in which the intent of the revelations is to alter political events. Exactly how, though, is a bit of a mystery, apart from embarrassing Democrats and further alienating Mr. Sanders’s supporters from Mrs. Clinton.
Evidence so far suggests that the cyberattack was the work of at least two separate agencies, each apparently working without the knowledge that the other was inside the Democrats’ computers. It is unclear how WikiLeaks obtained the email trove. But the presumption is that the intelligence agencies turned it over, either directly or through an intermediary. Moreover, the timing of the release, between the end of the Republican convention and the beginning of the Democratic one, seems too well-planned to be coincidental.