Hillary Clinton privately told a major Wall Street bank that her State Department was subject to cyber-attacks "every hour of every day," and that those attacks targeted employees' personal email accounts, hacked documents reveal.

Clinton said she was "very worried" about the state of the federal government's cyber-security efforts after witnessing how vulnerable State Department systems, including email accounts, were to malicious hackers, during remarks to employees of Deutsche Bank AG.

"We were attacked every hour of every day and not only through the State Department system, but also through individual, personal accounts, just really fishing for anything they could get," Clinton said.

A transcript of her remarks, which she made on October 2014, were attached to an email to campaign aides including chairman John Podesta, whose email account was breached by hackers believed to be acting in concert with the Russian government.

"I don't think we've yet taken it seriously enough as a nation," Clinton said of cyber-security generally. But she touted her own efforts to shore up vulnerabilities at State.

"I think this is a rolling threat that will only increase in intensity and so I appointed the first ever cyber security expert in the State Department," Clinton said.

However, probes into Clinton's email practices from the FBI and the State Department's inspector general found that she routinely disregarded the guidance of cyber-security experts in her own department.

FBI director James Comey concluded that Clinton and her staff, who conducted State Department business through email addresses hosted on a private server in Clinton's home, "were extremely careless in their handling of very sensitive, highly classified information."

The Clinton campaign did not immediately respond to a request for comment on her Deutsche Bank remarks.

In the course of its investigation, the FBI found that Clinton's private server was breached by a hacker using the web anonymity service Tor.

Emails released since then in response to Freedom of Information Act requests by the groups Judicial Watch and Citizens United reveal numerous attempts to breach the server through the accounts of top Clinton aides Doug Band and Huma Abedin.

Brian Pagliano, one of the staffers who set up the Clintons' personal email system, alerted staff in November 2010 to a handful of apparent attempts to illicitly access Abedin's and Band's clintonemail.com accounts.

Abedin sent an email two months later to Justin Cooper, another Clinton aide overseeing the email system, complaining that her "Clinton [black]berry" was not working.

"We were attacked again so I shut it down for a few min," Cooper replied.