The rise in hacking originating in China and Russia has been well-documented by security researchers. But it has been harder to distinguish between state-sponsored hackers and those just operating in the same geographic region, said Graham Cluley, senior technology consultant for security firm Sophos.
Some 30% of the malicious software is written by Chinese, Cluley said. But about 17% of those programs are designed to steal the passwords of users who play online games rather than intended for industrial espionage, he said.
"It's not all James Bond," Cluley said.
Hackers are also tough to trace since they can often control networks of other computers, called botnets, which can be used to carry out commands and attacks.
Botnet investigations are time-intensive and difficult for law enforcement since the computers are often in different countries, requiring international legal cooperation.
Spying to gain an advantage over a commercial competitor is nothing new, and it's hard to definitively blame China for it, said Peter Sommer, who teaches information systems security at the London School of Economics and also wrote "The Industrial Espionage Handbook."
The job of an industrial spy has also become a lot easier with the advent of the Internet, Sommer said. About 90% of intelligence collected by agents is "open source," or already public information.
"You no longer have to get into buildings and try and meet people," Sommer said.
Public websites of companies are rife with email addresses of employees who can be "spear-phished," or sent email with a malicious software such as a keystroke logger. The hacker uses social-engineering tricks in order to get the worker to open the attachment, opening up access to a company's network.