Can I hack a smartphone without internet?

Has your smartphone been hacked? How to find out

Stefan Wehrhahn

Has your smartphone been hacked? This question often leads first to the counter-question: Why should someone spy on me? You could say: Because it works. But there are certainly many other reasons. And spy programs are legally available.

EnlargeWhy would someone spy on my smartphone?
© Fotolia / valerybrozhinsky

The reasons for hacking a smartphone can be many and varied, from spying on business information to personal matters like litigation. Nowadays there are numerous mobile programs that make spying easier than ever. The offer is not only huge, but also absolutely legal. Although the software of the espionage programs is now very mature, you can still tell from certain signs whether you are affected yourself.

How to spot spy software

The evidence that suggests that a smartphone is being monitored, spied on or wiretapped are often very hidden. But if you know what to look out for, they can hardly be overlooked:

• Lower battery power: When a cell phone is tapped, it records all activities and transmits them to third parties. In addition, all calls being made in the vicinity can be listened to, even in standby mode. These processes cause increased power consumption, which means that the battery is drained faster. If you insert this battery into another device of the same model and it suddenly lasts longer there, the probability is high that your own smartphone is either defective or tapped.

• Heated battery: Even if the phone feels warm to the touch even though you haven't used it, this can be an indication that data is being secretly transferred. The temperature of the battery can therefore indicate possible eavesdropping activities.

• Activity despite not being used: If a smartphone is not in use, it should be completely quiet apart from calls and incoming messages. If there are still noises, the display suddenly lights up or it even restarts for no reason, someone may be controlling the device remotely.

• Unusual text messages: Spy programs send secret encoded text messages to your smartphone. If the program does not work properly, you can see such messages, mostly disjointed combinations of numbers, symbols or characters. If this happens regularly, a spy program may have been installed.

• Increased data consumption: Some less sophisticated spy programs cause the data volume to skyrocket when forwarding information. Accordingly, one should pay attention to whether the monthly data consumption increases for no reason. However, good spy programs require very little data volume and cannot be identified in this way.

• Interfering noises during telephone calls: If you can hear clicking or hissing on the phone, if the other party's voice sounds far away, or if it is only transmitted in fragments, it is possible that you are being eavesdropped. With phone signals now being transmitted digitally, such unusual noises can no longer be caused by poor phone lines.

• Long switch-off process: Before switching off a smartphone, all running processes must be terminated. If data is transmitted to third parties from your smartphone, this process must also be completed before switching off. If it takes longer than usual to switch off, especially after phone calls, after sending e-mails or text messages and after surfing the Internet, this could mean that information was just transferred to someone.

How to find spy programs on Android and iOS

With Android devices, spy programs can often be identified by specific files on the phone. If filenames contain terms like spy, monitor or stealth, this is a clear indication of a spy program.

If you actually find such files, it makes sense to have the device checked by a specialist. Simply deleting or removing files without knowing exactly how to do it is not recommended.

With the iPhone, the directories are not so easy to search. There is another way to do this by removing spy programs. All you have to do is update the operating system to the latest version through iTunes. This will remove both a possible jailbreak, i.e. the lifting of the usage restrictions of the operating system, and all programs that do not come from Apple. But before doing this, please back up any important data that is stored on the phone.

Basically, spy programs can be removed from both Android devices and iPhones by performing a factory reset. In this case, too, important data such as contacts, photos and music should be backed up beforehand, because these will also be deleted.

It also makes sense to set up a screen lock. This will prevent unauthorized access to the device in the future. For Android devices, there are also apps like App Notifier that notify you by email when a program is installed on your phone and warn you when someone tries to do unwanted activity on the device.

Have you been spied on?

If you find out that you are being monitored with the help of a spy program, you are initially shocked - mainly because most users do not even know that such programs exist.

However, when you realize that there are a multitude of powerful, easy-to-use spy programs around, it should be clear that smartphones also need to be protected. For this purpose, there are security apps that offer smartphones and the data stored on them effective protection against hackers and, for example, warn when unsafe apps are downloaded.