5 non-obvious ways to spy on you with your smartphone

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

You don't even need a GPS to reveal your location, and you can use a gyroscope to steal your password.

You probably know that your smartphone can very well be used against you. By hacking a gadget, you can gain access to its cameras or microphones. This means that everything that you shoot and say can be transferred to third parties. The possibilities of modern smartphone espionage are not limited to this. In theory, there are a number of other less obvious ways to get information about where you are and what you are doing right now.

1. Keylogger based on gyroscope data

All modern smartphones are equipped with a gyroscope. This sensor is needed to determine the exact direction of the tilt of the gadget, which can be used to automatically activate some functions or control a car in a racing game.

These sensors are becoming more and more accurate every year. In theory, their sensitivity to the slightest fluctuations can be exploited by intruders against you. This was proved by researchers at Northeastern University of Boston. With the help of a gyroscope and a microphone, they managed to create a fairly accurate keylogger.

A keylogger, or keylogger, is a software or hardware device that records various user actions: keystrokes on the keyboard, movements and mouse clicks, gestures on the touch screen.

When you use the on-screen keyboard, your smartphone tilts slightly with each touch. By recognizing the slightest displacement with a gyroscope, the keylogger can guess the approximate text you are typing. The options are adjusted based on the intensity of the sound emitted when the display glass is touched. The microphones of the smartphone are already helping with this. Using a combination of these sensors and a set of algorithms, the researchers were able to guess the keys pressed with an accuracy of 90–94% the first time.

2. Determination of location without GPS

Even with the GPS turned off, you can determine the location of the device using the used cell towers and Wi-Fi points with geolocation information associated with them. However, it is possible to obtain information about the user's location even without access to such data.

The same group of researchers from Northeastern University tried to demonstrate this using smartphone sensors, which applications can use without special permissions. The result of their work was a program that uses a gyroscope, an accelerometer and a magnetometer.

Taking as a basis the map of the area in which the person was, the application made it possible to track all movements in the car. An accelerometer was used to detect movement and stops. The magnetometer recorded the direction of movement. The gyroscope measured the angles of the turn, allowing you to accurately track when and in which direction the car was turning.

A special algorithm combined data from all these sensors and formed an approximate movement pattern based on them. It was compared with real routes in the area where the surveillance was carried out. Based on such data, it is quite possible to determine exactly where and when the user went, how much time he spent on it.

3. Tracking through banner ads

There is another way to determine the location of a person without direct access to the GPS data of his smartphone. This method was described by researchers at the University of Washington who used banner ads for mobile. The minimum deposit for placing such an ad through Google AdWords and Facebook was $ 1,000.

When purchasing such a banner, you can specify in which application and for which unique device identifiers the display is required. The researchers also pointed to a three-mile square geofence where ads were displayed in selected applications.

Each time the target phone used a given application, information about the device, time and location was sent to the banner holders. With this information, the research team was able to track the user's location within 25 feet (~ 7.6 meters). True, this is possible as long as the application remains open for four minutes or has been launched twice in the same place.

Of course, this method of tracking requires the constant use of a certain application. In part, this obstacle can be circumvented by placing banners in the most popular programs. It is also necessary to know in advance the specific advertising identifier of a specific person's device. However, even without it, this method may well be used to monitor the population of the selected location.

4. Viewing visited links through a light sensor

The ambient light sensor allows you to adjust the brightness of your smartphone's display. You will be surprised, but even this seemingly harmless sensor can be used against you.

Lukasz Olejnik clearly illustrated this by creating an application that, according to data from a light sensor, determines the color of links visited by a user. Simply put, the light emitted from your screen can be accurately detected by this sensor. This allows you to determine which web pages you have navigated to.

Websites can display different colors for links. For example, the text may be light blue if you haven't visited it before, but it will turn purple after the first click. The site itself, of course, cannot recognize in what color the link is displayed for a specific user, because the browser captures the transitions. However, if representatives of a web resource get access to the data of the light sensor of your smartphone, they can determine by the light emanating from the screen whether you have previously followed the displayed link or not.

This is especially noticeable on contrasting pages with dark text background and light highlighting of hyperlinks. As soon as you stumble upon them, the sensor detects an increase in the level of light from the screen. In theory, in this way, without your knowledge, you can create lists of all the pages you visit.

5. Identification of users and objects nearby

The vast majority of smartphones have a proximity sensor. It is he who is used to disable the touch screen when you call. Otherwise, during a call, your face would continue to press the buttons on the display.

This sensor not only detects that objects are close to the screen, but can also measure the distance to them. Each of us holds a smartphone at a different distance depending on height, arm length, vision and other factors. Based on all this information, the application may well differentiate users and their behaviors.

The accuracy of this method may not be high, but when combined with the same targeted mobile banners, advertisers can identify their target audience. In addition, using the proximity sensor, you can determine the distance to nearby objects around the user. And this can be an additional tip when tracking without using GPS.

Each of these methods has so far been described as theoretical. So far, none of them has become widespread. However, it is possible that this is only a matter of time.