Hewlett Packard Enterprise has allowed experts working with Russia to review the source code of cybersecurity software that is used by the U.S. Defense Department. The Pentagon uses HPE's ArcSight software to protect sensitive computer networks. The review of its code was conducted by Russian firm Echelon on behalf of a Russian defense agency that deals with cybersecurity issues. "All testing was done in HPE controlled sites and entirely under the supervision of HPE's cybersecurity specialists," HPE said.