HONG KONG (AP) — A U.S. security firm says the Chinese government might be using a smartphone app to spy on pro-democracy protesters in Hong Kong.

The firm, Lacoon Mobile Security, says activists have received a link to the application that says it was created by a protest group. The firm said once downloaded, the software gives an outsider access to the phone's address book, call logs and other information.

Lacoon said the technical details of the application "lead us to believe that the Chinese government are behind the attack."

China is, along with the United States and Russia, regarded as a leader in cyber warfare research. Security firms say they have traced an array of hacking efforts aimed at foreign governments and companies to computers in China.