It was just before noon in Moscow on March 10, 2016, when the first volley of malicious messages hit the Hillary Clinton campaign.
The first 29 phishing emails were almost all misfires. Addressed to people who worked for Clinton during her first presidential run, the messages bounced back untouched.
Within nine days, some of the campaign's most consequential secrets would be in the hackers' hands, part of a massive operation aimed at vacuuming up millions of messages from thousands of inboxes across the world.
An Associated Press investigation into the digital break-ins that disrupted the U.S. presidential contest has sketched out an anatomy of...