US Investigates Cyber Breach of Homeland Security Network

A cyber breach has affected an information-sharing network used to exchange sensitive data with partners, according to the US Department of Homeland Security.

The department said a recent cyber incident involved a "non-classified information-sharing environment" but provided no further details.

GovExec, which first reported the incident, said the breach targeted the Homeland Security Information Network (HSIN), a platform used to share sensitive but unclassified information with foreign law enforcement agencies, local authorities and other organizations.

Two sources familiar with the matter told the publication the breach is believed to have taken place between late May and early June.

US Senator Mark Warner, the top Democrat on the Senate Intelligence Committee, warned that although the network does not contain classified information, the information it holds is "highly sensitive" and its exposure could threaten national security.

Warner called on the Department of Homeland Security and the Department of Justice to carry out a comprehensive investigation to identify those responsible and determine what information may have been compromised.