In brief: US intelligence agencies believe China is building sophisticated cyberweapons that could "seize control" of satellites belonging to enemy Western nations, rendering them ineffective at supporting communications, weapons, intelligence, surveillance, and reconnaissance systems.

As reported by the Financial Times, a CIA-marked document on China's plans to develop cyberweapons that can deny, exploit or hijack enemy satellites was one of several classified files allegedly shared by 21-year-old Massachusetts Air National Guardsman Jack Douglas Teixeira on a Minecraft Discord group. They eventually ended up on Twitter, 4chan, and Telegram.

Washington says the plans to hijack Western satellites are part of China's goal to control information, something Beijing believes is a key "war-fighting domain."

One of China's attacks looks to mimic the signals that satellites receive from their operators, thereby tricking them into either being taken over entirely or malfunctioning during crucial moments in combat. It would knock out the abilities of satellites, which usually operate in clusters, to communicate with each other, relay signals and orders to weapons, and send back visual and intercepted data.

General B Chance Saltzman, the chief of the US Space Force, recently said that Washington is facing a "new era" of threats beyond Earth. He says China has deployed 347 satellites, including 35 launched in the past six months, designed to take on US forces in the event of a future conflict.

"The threats that we face to our on-orbit capabilities from our strategic competitors [have] grown substantially," Saltzman told CNBC "the congestion we're seeing in space with tracked objects and the number of satellite payloads, and just the launches themselves, have grown at an exponential rate."

"China continues to aggressively invest in technology meant to disrupt, degrade and destroy our space capabilities," Saltzman said.

One just has to look at Russia's invasion of Ukraine to see the importance of satellite communications in war. Russia launched a cyberattack on US telecommunications provider Viasat on February 24, the day of the invasion. The incident resulted in satellite modems that provide internet service for thousands of European customers, including many in Ukraine, being taken offline.

SpaceX Starlink satellites have been a particular annoyance for China. Back in May, Chinese military researchers were concerned about the potential threat posed by Starlink and urged the government to develop ways of destroying or disabling them. And in February, reports claimed the country planned to launch 13,000 satellites as part of a rival service to provide global internet, "suppress" Elon Musk's network, and carry out anti-Starlink missions.