This is the typo that gave Russian hackers access to Clinton campaign emails

Impact

As a Russian group of hackers called the Dukes was attempting to break into secure Democratic party networks, a simple typo may have set in motion a series of information leaks that played an unquantifiable role in Hillary Clinton's electoral defeat in November.

When the Dukes emailed Clinton campaign manager John Podesta with a falsified message asking him to provide his email password — a style of social engineering attack known as phishing — campaign aide Charles Delavan advised others the email was "legitimate" and "John needs to change his password immediately," the New York Times reported.

Delavan says he meant to type "illegitimate."

According to the Times, FBI investigators believe that set off the chain of events that ultimately gave the Russian team access to 60,000 campaign emails held in Podesta's account. Clinton campaign staffers did not realize their network was compromised for months.

The emails contained everything from unflattering revelations about Clinton staff and allies to transcripts of private speeches Clinton gave to financial institutions like Goldman Sachs. 

While many factors played a role in Clinton's defeat, the leaks were repeatedly cited by Republican nominee Donald Trump on the campaign trail. Coupled with another leak of Democratic National Committee emails showing DNC staff were hostile toward Vermont Sen. Bernie Sanders' campaign, the Russian effort likely had a hand in Trump's victory.

The lesson here is simple: If information security isn't really your thing, you might as well proofread your emails.