The private email account used by Hillary Clinton while she was secretary of state was targeted by Russia-based hackers, newly released emails show.
Hillary Clinton received at least five emails containing malware.
The “phishing” emails, disguised as speeding tickets, would have enabled the hackers to control her computer.
The infected computer would have sent information to at least three computers overseas, including one in Russia.
A spokesman for HillaryClinton said there was no evidence of a breach.
The hacking attempts were included in thousands of emails released by the State Department.
Hillary Clinton’s opponents have accused her of putting US security at risk by using an unsecured computer system.
The Democrat presidential hopeful says no classified information was sent or received.
The five emails, sent over a four-hour period in August 2011, show hackers had Hillary Clinton’s email address, which was not public, and contained a virus concealed as a speeding ticket from New York state, where she lives.
The email containing instructions to open and print the speeding ticket misspelled the name of the city concerned, Chatham, came from a supposed New York City government account and contained a “Ticket.zip” file of the kind usually picked up by commercial antivirus software.
Nick Merrill, a spokesman for Hillary Clinton’s presidential campaign, said there was no evidence to suggest she replied to the emails or opened the attachment.
“All these emails show is that, like millions of other Americans, she received spam,” he said.
The state department disclosed that Hillary Clinton used a private server during her time as secretary of state (between 2009 and 2013) after journalists requested copies of her government emails.
Hillary Clinton has admitted that her decision to use a private email server at her New York home was a mistake.
However, the latest set of her emails to be released also reveal frustration within the State Department at the technology it was using while she was in office.
In one email exchange Hillary Clinton’s then head of policy Anne-Marie Slaughter wrote that the department’s technology was “so antiquated” that high-level officials “routinely end up using their home email accounts to be able to get their work done quickly and effectively”.
Anne-Marie Slaughter suggested writing an opinion piece to highlight the problem and Hillary Clinton agreed the idea “made good sense”, but her chief of staff Cheryl Mills warned against “telegraphing” how often senior officials relied on their private email accounts to do government business because it could encourage hackers.
Barack Obama’s unclassified emails were accessed by Russian hackers who gained access to the White House computer system last year were, the New York Times has reported.
The breach was far more intrusive than previously admitted, the newspaper wrote.
Officials have conceded that sensitive information was in the unclassified system the hackers accessed.
The discovery of the hacking in October 2014 led to a partial shutdown of the White House email system.
The New York Times wrote: “The hackers, who also got deeply into the State Department’s unclassified system, do not appear to have penetrated closely guarded servers that control the message traffic from Mr. Obama’s BlackBerry, which he or an aide carries constantly.”
“But they obtained access to the email archives of people inside the White House, and perhaps some outside, with whom Mr. Obama regularly communicated. From those accounts, they reached emails that the president had sent and received.”
The publication quoted White House officials as saying that no classified networks were compromised, and that the hackers accessed no classified information.
Many senior officials have two computers in their offices, one which works on a highly secure classified network and another for unclassified communications, the paper said.
However, officials have conceded that the unclassified system often contains information that is considered highly sensitive, including schedules, email exchanges with ambassadors and diplomats, debate about policy and forthcoming personnel deployments and legislation.
The FBI has offered a record $3 million reward for information on Russian hacker Evgeniy Bogachev.
This is the highest reward the US authorities have ever offered in a cybercrime case.
Evgeniy Bogachev was charged last year in the US with being behind a major cybercrime operation that allegedly stole more than $100 million.
He was last seen in Russia, where he is believed to remain at large.
Arresting him may be difficult, as the US does not have an extradition treaty with Russia.
Evgeniy Bogachev, also known as “lucky12345” and “slavik”, is accused of running the GameOver Zeus attack network, thought to have infected more than one million computers.
Victims were tricked into downloading malware – malicious software – which then searched specifically for financial information.
Evgeniy Bogachev was charged last year on counts including conspiracy, wire, bank and computer fraud, and money laundering, after the FBI said it broke up the network.
He is one of the FBI’s most wanted cyber-criminals.
“This reward offer reaffirms the commitment of the US government to bring those who participated in organized crime to justice, whether they hide online or overseas,” the US State Department said.
The reward is being offered for information leading to the arrest or conviction of Evgeniy Bogachev.
The head of the FBI’s cyber crime division, Joseph Demarest, said Russia’s internal security agency had expressed an interest in working with the US on cybercrimes, according to Reuters, but did not link it to the Bogachev case.
Joseph Demarest also said the agency was aware of 60 different cyber-threat groups linked to nation-states, but gave no further details.