The Army has spent millions of dollars in the past year and a half to rebuild networks at major U.S. bases after hackers penetrated its systems, Army and industry officials said.

The incidents at the bases were serious enough that Army information technology officials pulled the plug on the connection to the Defense Department's Non-classified IP Router Network (NIPRNET).

As a result of the Army's network intrusions, Pentagon officials instructed the service to devise a plan to improve network security. Army IT officials have worked to improve network security and operations and to rebuild the networks at the facilities that were attacked.

The Army is developing an enterprise consolidation plan for next year that will reduce the number of networks and help improve the service's network defenses, Army and industry officials said.

The Army could spend millions of dollars repairing and upgrading the networks at two Army installations, said George Hermalik, Continental U.S. risk mitigation team leader in the Enterprise Systems Technology Activity (ESTA) in the Army's Network Enterprise Technology Command (Netcom). He spoke last week at the 2005 Army IT conference in Las Vegas.

Hermalik declined to specify what installations were involved in the effort. But Maj. Gen. Dennis Moran, director of information operations, networks and space in the Army's Office of the Chief Information Officer, said in a speech at the conference that Fort Hood, Texas, has a huge information security problem.

An industry official familiar with the situation said there have been hackings at Fort Hood, home of the 4th Infantry Division and the service's first digitized division, and Fort Bragg, N.C., the location of the 82nd Airborne Division and the service's elite paratroop forces. An Army IT official with knowledge of the events confirmed the hackings at Fort Hood, but would not comment on the other installation. He said remediation efforts have been ongoing at Fort Hood for the past two years.