2016 Presidential Campaign Hacking Fast Facts

(CNN)Here's a look at hacking incidents during the 2016 presidential race between Donald Trump and Hillary Clinton. For details about investigations into hacking and efforts to interfere with the election, see 2016 Presidential Election Investigation Fast Facts.

Timeline:
September 2015 - The FBI contacts the Democratic National Committee's help desk, cautioning the IT department that at least one computer has been compromised by Russian hackers. A technician scans the system and does not find anything suspicious.
November 2015 - The FBI reaches out to the DNC again, warning them that one of their computers is transmitting information back to Russia. DNC management later says that IT technicians failed to pass along the message that the system had been breached.
    March 19, 2016 - Hillary Clinton's campaign chairman John Podesta receives a phishing email masked as an alert from Google that another user had tried to access his account. It contains a link to a page where Podesta can change his password. He shares the email with a staffer from the campaign's help desk. The staffer replies with a typo - instead of typing "This is an illegitimate email," the staffer types "This is a legitimate email." Podesta follows the instructions and types a new password, allowing hackers to access his emails.
    April 2016 - Hackers create a fake email account and use it to send spear-phishing emails to more than thirty Clinton staffers, according to investigators. In the emails, the hackers embed a link purporting to direct the recipient to a document titled "hillaryclinton-favorable-rating.xlsx." The link directs the recipients' computers to a website operated by the hackers. That same month, hackers use stolen credentials to access the Democratic Congressional Campaign Committee computer network, stealing data with malware. They ultimately access 33 DNC computers and anonymously register a website called DC Leaks to publicize the release of documents.
    May-June 2016 - The hackers steal thousands of emails from the DNC server and begin to conceal their efforts.
    June 12, 2016 - During an interview on British television, WikiLeaks founder Julian Assange says that the website has obtained and will publish a batch of campaign emails.
    June 14, 2016 - The Washington Post reports hackers working for the Russian government accessed the DNC's computer system, stealing oppositional research on Trump and viewing staffers' emails and chat exchanges. The Kremlin, however, denies that the government was linked to the hack and a US official tells CNN that investigators have not yet concluded that the cyberattack was directed by the Russian government.
    June 15, 2016 - Crowdstrike, a cybersecurity firm hired by the DNC, posts a public notice on its website describing an attack on the political committee's computer network by two groups associated with Russian intelligence. According to the post, two groups called "Cozy Bear" and "Fancy Bear" tunneled into the committee's computer system. In response, the hackers create a persona called Guccifer 2.0, a self-described Romanian blogger who claims that he alone conducted the theft.
    July 22, 2016 - Days before the Democratic National Convention, WikiLeaks publishes nearly 20,000 emails hacked from the DNC server. The documents include notes in which DNC chair Debbie Wasserman Schultz insults staffers from the Bernie Sanders campaign as well as messages that suggest the organization was favoring Clinton rather than remaining neutral. Wasserman Schultz resigns as DNC chair in the aftermath of the leak.
    July 25, 2016 - The FBI announces it has launched an investigation into the hack. Officials tell CNN they think the cyberattack is linked to Russia.
    July 27, 2016 - During a press conference, Trump talks about Clinton's use of a private email server while she was secretary of state and calls on hackers to find deleted emails. "Russia, if you're listening, I hope you're able to find the 30,000 emails that are missing," says Trump. Newt Gingrich, a Trump surrogate, defends Trump in a Tweet, dismissing the comment as a "joke."
    August 12, 2016 - Hackers publish cell phone numbers and personal email addresses for Nancy Pelosi and members of the Democratic Congressional Campaign Committee.
    September 1, 2016 - During an interview with Bloomberg News, Russian President Vladimir Putin says that he and the Russian government have no ties to the hackers. He says that the identity of the culprit or culprits is not as important as the content of the leaks and ultimately the hackers have revealed important information for voters.
    September 22, 2016 - Democrats Dianne Feinstein and Adam Schiff, ranking members of the Senate and House Intelligence Committees, issue a joint statement declaring that based on information they received during congressional briefings, they believe Russian intelligence agencies are carrying out a plan to interfere with the election. They call on Putin to order a halt to the activities.
    September 26, 2016 - During a presidential debate, Trump questions whether the DNC cyberattack was carried out by a state-sponsored group or a lone hacker. "It could be Russia, but it could also be China. It could also be lots of other people. It also could be somebody sitting on their bed that weighs 400 pounds."
    October-November 2016 - Over the course of a month, WikiLeaks publishes more than 58,000 messages hacked from Podesta's account.
    October 6, 2016 - DC Leaks publishes a batch of documents stolen from Clinton ally Capricia Marshall.
    October 7, 2016 - The Department of Homeland Security and the Office of National Intelligence on Election Security issue a statement declaring that the intelligence community is "confident that the Russian Government directed the recent compromises of emails from US persons and institutions." According to the statement, document releases on websites WikiLeaks and DCLeaks mirror the methods and motivations of past Russian-directed cyberattacks.
    November 29, 2016 - Democratic senators send a letter to President Barack Obama calling on intelligence agencies to declassify informat