The US Treasury Department has been hacked by suspected hackers

Foreign government-backed hackers have been monitoring the internal email exchanges between the US Treasury and an agency responsible for Internet and telecoms policy, according to people familiar with the matter.

“The U.S. government is aware of these reports, and we are taking all necessary steps to identify and remedy any possible problems associated with this situation,” said John Ullyot, a spokesman for the National Security Council.

The US intelligence community is concerned that hackers targeting the National Telecommunications and Information Administration (NTIA), part of the Treasury and Commerce departments, are using similar tools to break into other government agencies, according to three people briefed on the matter. The person did not identify the other agencies.

The hack was so serious that the National Security Council convened a Meeting at the White House on Saturday, a source said.

The hack involved NTIA’s office software, Microsoft’s office365. The emails of the agency’s staff had been monitored by hackers for months, the sources said.

A Microsoft spokesman didn’t immediately respond to a request for comment.

Hackers believed to be working for Russia have been monitoring internal email exchanges between the Treasury Department and the NTIA, according to people familiar with the matter.