Hong Kong's pro-democracy protesters are under threat from a computer virus that has the ability to spy on iOS users, Reuters reports. The software is called Xsser and can track calls, teal text messages, photos and more or less anything private stored on a phone.     

Researchers from San Francisco-based company Lacoon Mobile Security uncovered the virus while investigating another piece of spyware that infects Android operating systems. Lacoon chief executive Michael Shaulov said that he had never seen a cyberattack on iOs as elegant or powerful as Xsser. 

"This is one the most interesting developments we have seen," he said. "It’s the first real indication that really sophisticated guys are shifting from infecting PCs or laptops to going after iOS devices."

Shaulov believes Xsser is going after Hong Kong protesters, who have gathered in tens of thousands to demonstrate against the growing influence of Chinese authorities in Hong Kong elections. Researchers believe that the virus is of Chinese origin, as the code used to control the server is written in Chinese.

Hong Kong protesters are more than aware that communication could be blocked or monitored. Earlier this week, China took down Instagram on the mainland to stop citizens seeing images of Hong Kong police deploying tear gas against pro-democracy protesters. Over 100,00 demonstrators have also downloaded messaging apps like FireChat, which allow users to communicate via Bluetooth if the government blocks 3G.

But if you're an Apple user on the streets of Hong Kong, remember that there's every possibility that you're being watched and listened to. Be careful who you talk to and how you do it.