For a device to become infected, no matter whether it is a mobile phone or a computer, it is a nuisance if we catch it in time, but it can become a very serious problem if we do not take the appropriate measures. Android, like any operating system, is not invulnerable to malicious apps And although Google is taking steps to make it more secure, there are always chances that we have a problem.
If we detect that our Android mobile is bad or behaves strangely (such as showing us banners randomly or shocking our contacts with advertising messages) it is time to take action on the matter and give it a good cleaning. Whether you have a problem or not, this guide will help you know everything you need to do to make it look like new or prevent it from happening to you.
How does a virus enter my Android?
Before we start with the practice, let’s do a brief review of the theory by answering a fundamental question. In the imagination of many people, a computer virus can enter without our realizing it and sometimes doing things as innocuous as for example opening a web page or an email from a stranger. The reality is a bit different and in Android it takes a little more for our mobile to get infected or malware is installed. In fact, we have to open the door ourselves.
On Android, a malicious application does not enter as such and we are the ones who give you permission. Obviously we do not do it consciously and what these dangerous apps try is to sneak in without us noticing, such as games that ask for permission to use the microphone to listen to our conversations and sell advertising data.
This is usually the usual entry for a good part of malware: an app that seems innocent but begins to ask us for all kinds of permissions or to take control as administrator of the mobile so that we cannot uninstall it at the first change. This is exactly what happens with the new fake SMS scam that tells us that we have a package to collect.
Our first tip is common sense: let’s not accept things as they appear on the screen and in the face of any element that seems suspicious or strange, let’s not hesitate to stop and see what exactly that is.
Malicious applications on Android enter because we give them permission without us noticing. Therefore, the best way to avoid it is to be vigilant.
With this brief explanation done, it is time to explain the different actions we can take to eliminate malware and other types of viruses. The order we have chosen goes from the simplest operation to the one with the greatest impact. Our advice is that if you have a real problem with your Android, read it in order and with patience because the solution you need may not be the most drastic of all those we offer in this guide.
Disable the installation of unknown apps
Android by default only allows the installation of applications that are on Google Play and if a manufacturer has its own app store (such as Samsung) it also gives you permission to authorize them. In the Settings menu of our mobile we have an option that allows us to install content in APK format (similar to the .EXE of a Windows PC) and by default it is deactivated.
If this is the first time you’ve read about this option, it’s probably because you’ve never needed it. Activate this option and start downloading APK files from the Internet without knowing where they come from it is the main gateway for malware. If you have no real need to install something that is not on Google Play, disable it and leave it as it came by default.
To make sure that everything is fine, enter your mobile settings and in the search section, type “Install unknown applications”. Within this section you will see a list of applications with a text below that should be ‘Not allowed’. If ‘Allowed’ appears in any of them, click on it and change the settings, so you will be safe.
What real and safe reasons are there to install an APK from an unknown source?
Installing unknown apps is not always dangerous. There are cases in which we may need this option, such as:
Activate this option It must be a decision that is made fully consciously and intentionally by the user. If a supposedly official app asks you to allow the installation of unknown apps (as is the case with FedEx), be suspicious.
In which cases should we not install an application manually?
- If we have clicked on a suspicious-looking banner on a website.
- If we receive a suspicious link by mail or SMS.
- Applications with dubious premises such as customizing WhatsApp or apps that tell us that they will help us spy on someone else’s mobile.
- Pirated paid apps and games for us to download for free.
- Any content that promises us to earn easy money.
I know that some of the things I mention in this guide are very obvious, but be careful. Installing apps from unknown sources is tricky business if we do not know with certainty what it is that we do. If we want to make sure that this option is deactivated, we have to go to the “Settings” menu of our mobile and in “Security” deactivate the tab (if activated) of “Install applications from unknown sources”.
Have we granted any strange permission?
Now that we have closed the door to installing applications of unknown origin, it is time to start solving our problem. Any mobile with Android 5.0 Lollipop or a higher version have a permission system by which when we open any application for the first time it will ask us for access to different parts of our Android as we can see in the images that you have above these lines. Be careful because although it is effective, it is not unbeatable.
Does it sound like you have installed an application recently that has asked for strange permissions? It is normal that you have given ‘Accept’ without noticing what it is, but it may be that that flashlight app that you just downloaded or that generic-looking free game has wanted to access your phone or the contact list for malicious purposes.
The permission system in Android can save us from many attacks if we are attentive when we open an app for the first time.
It does not matter if it is a manually installed application or an app that we have just downloaded from Google Play, the problem of permissions is present in both and we have to be very careful because it is easy for them to enter us here. If you are convinced, it is as simple as uninstalling it and looking for an alternative.
What permissions are the most delicate on Android?
- Storage: an app can save content and access it in the memory of our Android.
- Camera: Take photos and record video. If you don’t need it strictly, please deny it.
- Contacts:: access our agenda, their names, telephone numbers and emails.
- Microphone: allows you to record or listen. Be very careful with him.
- SMS– Send text messages, for example to premium services.
- Telephone: make calls to an application, beware.
- Location: share and access the position we are in.
- Accessibility: designed for accessibility apps, for example so that blind people can interact with the phone.
If you suspect a Google Play app but are not sure that it has malicious permission, from the app store web or from the store itself on the mobile you can see what permissions it is requesting. You just have to go to the bottom and in the ‘Additional Information’ section you will see a section that says ‘Permissions’. We click on ‘See details’ and everything will appear well broken down there.
From your Android you can also check it within the ‘Applications’ menu in ‘Settings’ you will see that there is a permissions option and There it will list all the elements and within each one of them the apps to which we have authorized. If we see something strange, we just have to deactivate the switch in each of them to ban it forever.
Identify malicious applications
Let’s assume that we have not been able to find any application with ‘strange’ permissions and yet our Android continues to fare. We go with another option that is on any moderately updated device: identify applications by the type of function they do. Within the ‘Settings’ menu, in ‘Applications’ we will find an option (usually hidden in the upper right corner) where we will find the special access apps:
- Device administrators.
- Apps that can be displayed on top.
- Apps that change system settings.
- Access to notifications.
- Use Premium SMS services.
- Access to usage data.
The list is longer but these categories are the most critical since they are the most susceptible to a malicious attack: from sending SMS at a gold price to apps that want to pass themselves off as administrators and thus prevent us from uninstalling them easily. Go through each category and see if there are any applications that should not be there. Have you found it? Turn it off.
Now that we have done an exhaustive investigation and analysis of malicious applications on our Android and we have found them, it’s time to eliminate them. To do this, it is as simple as going to ‘Applications’ in the ‘Settings’ menu, clicking on it and clicking on uninstall. In a few seconds the app will have disappeared from our list and our problem will most likely have disappeared.
In most cases we will find ways to uninstall a malicious application.
Can’t delete an app? It is normal, some malicious apps ask for administrator permissions during installation to hook into the system and prevent us from deleting them with this simple procedure. Fortunately there is a solution. Within the ‘Security’ menu there is a section called ‘Device administrators’. If you don’t see it, it’s probably hidden within a menu called ‘Other Settings’. The nomenclature may change depending on the software layer that your Android carries.
From there we can see if there is any application that …