Why it's Dangerous: Dangerous Permissions | Complete Security

Android has a very good defence mechanism - an app permission system. Basically, it is a set of actions that the system allows the application to perform. The fact is that by default all applications in Android run in an isolated environment - the so-called "sandbox". And in order to do something with something, so to speak, public, they need to get permission.

These permissions are divided into several categories, but the most important are only two of them - "Normal" and "Dangerous".

The General group includes things like Internet access, creating shortcuts, Bluetooth connectivity, and so on. These permissions are issued to applications without the user's consent, that is, the system does not ask you about anything.

But in order to get one of the "Dangerous" permissions, the application must ask the owner of the device if he agrees to issue it. Why are "dangerous" permissions dangerous and should you issue them to applications?

The Dangerous category includes nine permission groups that are somehow related to the security of user data. In turn, each of the groups contains several permissions that the application can request. If the user has already approved one of the permissions in this group, the application will automatically receive all other permissions from the same group - without a new request to the user. For example, if an application has already managed to request and receive permission to read SMS, then later it will automatically receive permission to send SMS, receive MMS, and all other permissions from this group.

The calendar

View events in the calendar (READ_CALENDAR).

Changing the events already in the calendar and adding new ones (WRITE_CALENDAR).

Why it is dangerous: If you actively use an electronic diary, then access to it will allow you to find out everything about what you did in the past, do today and are going to do in the future - a real find for a spy. Also, some crookedly written application can inadvertently erase important appointments from the calendar.

Camera

Using the camera (CAMERA) - the ability to take photos and record videos.

Why dangerous: The application can take a photo or record a video at any time without warning you about it.

Contacts

Reading contacts (READ_CONTACTS).

Modifying existing contacts or adding new contacts (WRITE_CONTACTS).

Access to the list of accounts (GET_ACCOUNTS).

Why it's dangerous: Allows the application to get hold of your entire address book - this data will be very welcome to spammers and scammers. Also allows access to the list of all accounts with which you log into applications on this device - Google, Yandex, Facebook, Vkontakte, and so on.

Location

Approximate location access (ACCESS_COARSE_LOCATION) - based on data about mobile network base stations and Wi-Fi access points.

Access to exact location (ACCESS_FINE_LOCATION) - based on GPS data.

Why it is dangerous: Allows the application to track all your movements. For example, crooks may find out that you are on vacation and try to visit your home.

Microphone

Microphone sound recording (RECORD_AUDIO).

Why it is dangerous: The application will be able to record audio everything that happens near the smartphone. All your conversations. Not just by phone.

Telephone

Read phone status (READ_PHONE_STATE), including your phone number, cellular data, outgoing call status, and so on.

Making calls (CALL_PHONE).

Reading the call list (READ_CALL_LOG).

Changing the call list (WRITE_CALL_LOG).

Adding voicemail (ADD_VOICEMAIL).

Using IP telephony (USE_SIP).

Management of outgoing calls (PROCESS_OUTGOING_CALLS), including viewing the number you are currently calling, the ability to end a call or forward it to another number.

Why it's dangerous: By granting application permission to this group, you allow it to perform almost any action that relates to voice communication. The app will be able to find out when and to whom you called. Or call anywhere at your expense, including "very paid" numbers.

Sensors

Access to data from health sensors (BODY_SENSORS), such as a heart rate monitor.

Why it is dangerous: Allows the application to monitor what is happening to your body using information from sensors of the corresponding category if you have them and you use them (the motion sensors built into the smartphone are not included in this category).

SMS

Sending SMS (SEND_SMS).

View SMS in smartphone memory (READ_SMS).

Receiving SMS (RECEIVE_SMS).

Receiving WAP push messages (RECEIVE_WAP_PUSH).

Receiving incoming MMS (RECEIVE_MMS).

Why it's dangerous: Allows the app to receive and read all of your text messages. And also send SMS (of course, at your expense) - for example, to subscribe you to some paid "service".

Memory

Reading from memory or memory card (READ_EXTERNAL_STORAGE).

Writing to memory or memory card (WRITE_EXTERNAL_STORAGE).

Why it is dangerous: Provides the application with the ability to read, modify and delete any of your files stored in the smartphone's memory.

How to configure app permissions

It is worth paying close attention to the permissions requested by the application. If a game or photo-editing application requests access to your current location, this is most likely not normal - such applications do not need this information. But the GPS navigation application really needs it - but, in turn, there is absolutely no need to give it access to contacts or SMS.

If the rights requested by the application look too suspicious, it is better not to install such an application at all. Or, you can simply not allow him access to features and data that you do not want to share.

In Android version 6 and newer, applications display a request to the user at the moment when they need one or another of the "dangerous" permissions. If you do not agree to allow the application access, then you can simply click the "Deny" button. However, in the event that the application really needs one or another permission, errors may occur in its operation. In addition, the list of issued permissions can be checked and changed at any time in the operating system settings. To do this, go to Settings -> Applications.

Then there are two options. First, you can view all the permissions granted to a specific application: to do this, click on the name of the application you are interested in and select Permissions.

Second, you can look at the full list of applications that have requested or may request one of the "dangerous" permissions. For example, find out which applications would like to request access to your contacts and which ones are already allowed, as well as deny it to those of them whom you do not trust. To do this, click on the gear in the upper right corner and select Application Permissions.

Thus, in order, for example, to send an SMS, the application will need to ask the user for permission once, after which the user can deny the application this right at any time by simply moving the circle in the settings.

Special rights

In addition to the permissions that fall under the Dangerous category, there are a few other app rights to be aware of in Android. If an application asks for such rights, this is a reason to think carefully and check if you have come across a Trojan.

Accessibility

Having these rights in the app allows it to make it easier for users with disabilities such as low vision or hearing problems to use the app or device. But at the same time, the Android system is designed in such a way that the same set of capabilities turns out to be a very convenient tool for malicious applications. With these rights, Trojans can intercept data from other applications, including text entered by the user. Moreover, using these capabilities, malware can even buy apps from the Google Play Store.

Default SMS app

Many Trojans try to become the default application for working with SMS, because this allows them not only to read SMS but also to hide them from the user, even in modern versions of Android. For example, Trojans may need this in order to intercept one-time codes to confirm bank transactions.

Permissions to display your window on top of other applications

With these rights, Trojans can display their phishing windows on top of other applications, such as mobile banks or social networks. It seems to you that you are entering your username and password into the window of a real application - but in fact, this is happening in a fake window created by the Trojan, and the account data is leaked to the attackers.

Device administrator rights

With these rights, the application can, among other things, change the password, lock the camera or even delete all data from the device. Many Trojans ask for these rights since the application that is the device administrator is much more difficult to remove.

Superuser rights

These are the most dangerous rights. In normal mode, an application does not provide for such rights in Android, but some Trojans are able to obtain superuser rights themselves by exploiting vulnerabilities in the system. The most unpleasant thing is that the fact that an application has superuser rights devalues ​​all other protective mechanisms: using these rights, the malware can perform any action in the system, regardless of what permissions it has been granted. It is worth noting that even the new system for working with permissions, which appeared in Android 6, does not protect against malware, it only provides the user with the opportunity to prevent the loss of data or money... For example, the Gugi Trojan persistently asks the user for permission to overlap other applications, justifying this by the need to work with windows. Having obtained these rights, the Trojan blocks the operation of the device with its window until it obtains all the other rights it needs.

Conclusion

Not all apps should be allowed to do whatever they want on the smartphone. And it is better not to give some permissions at all - since Android 6 and newer allows it. However, there are some applications that really need a lot of different rights. For example, antivirus complete security programs need not only permission to access files, but much more in order to function properly, to be able to scan the system and proactively defend against threats. However, you cannot blindly grant permissions even to applications you trust. Just before you give these permissions, consider whether this particular application really needs them. Such vigilance, however, does not protect against the fact that some malware will gain rights itself through vulnerabilities in the system. Therefore, it is important not only to properly configure permissions for relatively "peaceful" applications that hunt for your personal data but also to have the means to detect much more dangerous malware - do not forget to install a reliable antivirus on your Android device.