The DDoS attack has caused network failure in some cases.
Security researchers claim that cyber attacks on organisations supporting pro-democracy activists in Hong Kong are reportedly backed by China.
The attackers are launching DDoS attacks against websites promoting the movement, reported cyber forensics firm FireEye.
Experts have discovered a link between attacks on online media in Hong Kong and cyber attacks on other targets that originated in China.
The report suggests that the Apple Daily publication has been targeted by the Distributed Denial of Service attacks (DDoS), which took down the email system of the organisation for hours. Next Media was also at the receiving end of the attack when hackers caused network failure.
FireEye said: "We’ve discovered an overlap in the tools and infrastructure used by China-based advanced persistent threat (APT) actors and the DDoS attack activity."
"We believe that these DDoS attacks are linked to previously observed APT activity, including Operation Poisoned Hurricane.
"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."
Other security researchers also suggest that Hong Kong protesters have been hit by iOS and Android spyware.