Rome wasn't breached in a day.

In the months leading up to the 2016 US presidential election, Russian hackers ran a sophisticated campaign, infecting more than 30 computers and stealing more than 50,000 emails, in an effort to sway the vote in Donald Trump's favor.

On Monday, President Trump met with Russian President Vladimir Putin and denied the allegations, siding with the Russian leader over evidence detailed by US intelligence agencies. The White House didn't respond to a request for comment.

This comes after special counsel Robert Mueller indicted a dozen Russian military officers linked to cyberattacks against Hillary Clinton's campaign, the Democratic National Committee and the Democratic Congressional Campaign Committee. According to Friday's indictment, these efforts started around March 2016 and lasted for months afterward.

Here's a timeline of how the 12 Russian operatives accessed thousands of emails and planned their release, according to the indictment. (Click the image to open in a new window.)

First published, July 16 at 2:10 p.m. PT.
Update, July 17 at 6:02 a.m. PT: Adjustments made to timeline.