NSA briefed White House officials on private email and cell phone risks: Source

— -- White House officials in the early days of the Trump administration were given security briefings on the dangers of using personal devices, like laptops and cell phones, and the risks of using personal email accounts for government work, a source familiar with the program tells ABC News.

The briefings, conducted by the National Security Agency (NSA), were held in the White House situation room, the source said. Briefers demonstrated how cell phones and other devices could be compromised using publicly available tools, allowing outsiders to eavesdrop and take pictures, audio or video. In secure areas, these techniques could be used by foreign adversaries to steal sensitive government secrets.

The briefings, first reported by Politico, are part of the security training given to every new administration. For staffers who are unaccustomed to working in secure spaces and with classified materials, the briefings are designed to raise awareness about the risks of using personal devices and email accounts.

NSA officials told White House officials that using personal email or personal devices could compromise sensitive information. Forwarding emails from personal accounts to work accounts could introduce malware into government systems.

The White House has launched a review of all staff usage of personal or private email accounts after revelations that six senior officials, including President Donald Trump's son-in-law and senior adviser Jared Kushner, have used private email to conduct personal business.

The probe is focused on emails on the White House server sent to and from the private accounts of all staff, sources said.

All West Wing staff are required to comply with the Federal Records Act, ensuring any personal emails related to government business are preserved as official records. Officials said the policy was thoroughly articulated to staff during the transition and enforced from day one.

The internal White House review comes after the leaders of the House Oversight Committee opened an investigation earlier this week into the use of private email and encrypted communications software at the White House.

ABC News' John Santucci and Devin Dwyer contributed to this report.