Pentagon Takes Aim at China Cyber Threat

The U.S. is warning about the Chinese military's use of civilian computer experts in clandestine cyber attacks repeatedly aimed at American companies and government agencies.

The Pentagon says the People's Liberation Army is using "information warfare units" to develop viruses to attack enemy computer systems and networks. Those units include civilian computer professionals.

The assertion was made in a report this week. It illustrates the difficulties in dealing with cyber espionage that officials believe but can't always prove is coming from China.