"All countries who can do conduct cyber operations," said Alastair MacGibbon, the former director of the Australian Federal Police's High Tech Crime Center.
"I think the thing that has upset people mostly about the Chinese is ... that they're doing it on an industrialized scale and in some ways in a brazen and audacious manner," said MacGibbon, who now runs an Internet safety institute at the University of Canberra.
China's ruling party has ambitious plans to build up state-owned champions in industries including banking, telecoms, oil and steel. State companies benefit from monopolies and other official favors but lack skills and technology.
Last year, a group of Chinese state companies were charged in U.S. federal court in San Francisco in the theft of DuPont Co. technology for making titanium dioxide, a chemical used in paints and plastics.
In 2011, another security company, Symantec Inc., announced it detected attacks on 29 chemical companies and 19 other companies that it traced to China. It said the attackers wanted to steal secrets about chemical processing and advanced materials manufacturing.
In Australia, a report by the attorney general this week said 20 percent of 225 companies surveyed had experienced a cyberattack in the previous year.
Australian mining companies make a tempting target because of their knowledge about global resources, said Tobias Feakin, head of national security at the Australian Strategic Policy Institute, a think tank.
As Chinese resource producers expand abroad, "you could see the motivation for understanding the Australian competition and infiltrating their systems," Feakin said.
China has long been cited by security experts as a center for Internet crime. They say some crimes might be carried out by attackers abroad who remotely control Chinese computers. But experts see growing evidence of Chinese involvement.
Few companies are willing to confirm they are victims of cyberspying, possibly fearing it might erode trust in their business.
"When companies admit their servers were hacked, they become the target of hackers. Because the admission shows the weakness, they cannot admit," said Kwon Seok-chul, president of Cuvepia Inc., a security firm in Seoul.
An exception was Google Inc., which announced in 2010 that it and at least 20 other companies were hit by attacks traced to China. Only two other companies disclosed they were targets. Google cited the hacking and efforts to snoop on Chinese dissidents' email as among reasons for closing its China-based search service that year.
Mandiant cited the example of an unidentified company with which it said a Chinese commodity supplier negotiated a double-digit price increase after attackers stole files and emails from the customer's chief executive over 2½ years beginning in 2008.
"It would be surprising if APT1 could continue perpetrating such a broad mandate of cyberespionage and data theft if the results of the group's efforts were not finding their way into the hands of entities able to capitalize on them," the report said.
AP Technology Writer Youkyung Lee in Seoul, South Korea, and AP writers Kristen Gelineau in Sydney and Eric Talmadge in Tokyo contributed to this report.