McAfee, the computer-security firm, has uncovered evidence of the hacking of more than 70 government and private organizations—and experts have fingered China as the likely culprit. Targets include the Associated Press, the International Olympic Committee, a U.S. Department of Energy lab, and a dozen U.S. security firms. All the evidence came from a single server, and McAfee said hundreds of other servers have been used in similar attacks. While McAfee did not point the finger at a culprit, a computer expert familiar with the study said the attacks, the biggest ever recorded, appear to have originated in China. The hackers were apparently after information on such matters as U.S. military systems, satellite communications, electronics, and natural-gas companies.