Senior military leaders took the exceptional step of briefing President George W. Bush this week on a severe and widespread electronic attack on Defense Department computers that might have originated in Russia, posing unusual concern among commanders and potential implications for national security.
Defense officials would not describe the extent of damage inflicted on military networks. But they said the attack struck hard at networks within U.S. Central Command, the headquarters that oversees U.S. involvement in Iraq and Afghanistan, and affected computers in combat zones.The attack also penetrated at least one highly protected classified network.
Military computers are regularly beset by outside hackers, computer viruses and worms. But Defense officials said the most recent attack involves an intrusive piece of malicious software, or "malware," apparently designed specifically to target military networks.
"This one was significant; this one got our attention," said one Defense official, speaking on anonymity when discussing internal assessments.
Although officials are withholding many details, the attack underscores the increasing danger and potential significance of computer warfare, which defense experts say could one day be used by combatants to undermine even a militarily superior adversary.
Bush was briefed this week on the threat by Navy Adm. Michael G. Mullen, chairman of the Joint Chiefs of Staff. Mullen also briefed Defense Secretary Robert M. Gates.
Military electronics experts have not pinpointed the source or motive of the attack and could not say whether the destructive program was created by an individual hacker or whether it had Russian government sponsorship. Defense experts might never be able to answer such questions, officials said.
The Defense official said the military has also not learned whether the software's designers might have been specifically targeting computers used by troops in Afghanistan and Iraq.
However, suspicions of Russian involvement come at an especially delicate time because of sagging relations between Washington and Moscow and growing tension over U.S. plans to develop a missile defense system in Eastern Europe. The two governments have also traded charges of regional meddling after U.S. support for democratic elections in former Soviet states and recent Russian overtures in Latin America.
