Scientists from the Technical University of Darmstadt and Zhejiang University recently discovered a way for cyber attackers to hijack users’ touchscreens without being connected to the device – by using electromagnetic interferences.

How it works

 According to the scientists’ latest research project, by using a device to emit a signal that manipulates the electromagnetic field around a nearby smartphone, attackers can “inject fake touch points into [the] touchscreen without the need to physically touch it.” Aptly nicknamed “GhostTouch,” this attack technique has the potential to accomplish a variety of smartphone functions, from answering phone calls to clicking on a malicious link. The Hacker News reports:

“The attack, which works from a distance of up to 40mm, hinges on the fact that capacitive touchscreens are sensitive to EMI, leveraging it to inject electromagnetic signals into transparent electrodes that are built into the touchscreen so as to register them as touch events.

The experimental setup involves an electrostatic gun to generate a strong pulse signal that’s then sent to an antenna to transmit an electromagnetic field to the phone’s touchscreen, thereby causing the electrodes — which act as antennas themselves — to pick up the EMI.

This can be further fine-tuned by tweaking the signal and the antenna to induce a variety of touch behaviors, such as press and hold and swipe to select, depending on the device model targeted.”

What GhostTouch means for smartphone users

 While a GhostTouch attack requires the interfering device to be near the target device (less than 1.57 inches or closer, to be exact), researchers say that the technology is still dangerous, as the interfering device can be controlled from farther away. As the research team recently stated:

“In places like a cafe, library, meeting room, or conference lobbies, people might place their smartphone face-down on the table… An attacker may embed the attack equipment under the table and launch attacks remotely.”

So far, nine different smartphones have proven to be susceptible to GhostTouch, including models by Galaxy, Huawei, and Apple.