A hacker penetrated an unclassified Pentagon email system, prompting authorities to take as many 1,500 accounts offline, US defense officials, quoted by an AFP report said.
'Elements of the unclassified email system were taken offline yesterday afternoon due to a detected penetration,' US Defense Secretary Robert Gates was quoted by the AFP report as saying.
'A variety of precautionary measures are being taken. We expect the system to be online again very soon,' Gates said.
Earlier, a congressional panel disclosed that hackers also have succeeded in penetrating computers at the Department of Homeland Security, the lead government agency in providing security against cyber attack, the AFP report said.
'What does this mean‾ It means terrorists or nation states could be hacking Department of Homeland Security databases, changing or altering names to allow them access to this country, and we wouldn't even know they were doing it,' the report quoted Representative James Langevin as saying.
The Pentagon email system carries 'routine email' involving administrative manners but not classified information related to military operations, Colonel Gary Keck, a Pentagon spokesman said.
Gates said the Defense Department computers are under constant attack, but he could not say why this attack unlike others forced authorities to take down part of the system.Pentagon officials would not comment on the source of the attack, or whether the hacker was able to read email sent over the system, the AFP report further said.