Online attacks aimed at thwarting pro-democracy activists in Hong Kong, who have been protesting since September for a greater say in choosing a leader, can be traced back to China, FireEye Inc., a cybersecurity forensics firm, said in a report Monday.

“We’ve discovered an overlap in the tools and infrastructure used by China-based advanced persistent threat (APT) actors and the DDoS attack activity,” FireEye said in the report. DDoS, or distributed denial of service, as the name suggests, refers to blocking access to the Internet and other networks. APT is jargon to describe an ongoing hacking effort to breach online security.

According to FireEye, its experts have discovered a link between attacks on online media and other sites that the city's protesters relied on and previous cyberattacks on other targets that originated in China, according to the report.

“This correlation sheds light on the potential relationships, symbiosis and tool sharing between patriotic hacker activities designed to disrupt anti-government activists in China, and the APT activity we consistently see that is more IP theft and espionage-focused,” FireEye said.

The cybersecurity firm concluded that a “common quartermaster” existed between the attacks on Hong Kong's pro-democracy protesters and the earlier data-theft activities, even though it was inconclusive that the same actors might be responsible.