"We found a series of software flaws," explained Isaac Mao, a blogger and social entrepreneur in China, as well as a research fellow at Harvard University's Berkman Center for Internet and Society.

For example, he said, tests had shown that communications between the software and the servers at the company that developed the program were unencrypted.

Mr. Mao told BBC News that this could allow hackers to "steal people's private information" or "place malicious script" on computers in the network to "affect [a] large scale disaster."

For example, a hacker could use malicious code to take control of PCs using the software.

"Then you have every computer in China potentially as part of a botnet," Colin Maclay, also of Harvard, told BBC News.