Your Android smartphone's security is important and you can protect it by paying attention to the permissions you grant to installed apps
Every time you download a new app on your Android smartphone, the permissions that are granted are limited for security reasons. In fact, often when you open the app, it will ask you to allow or deny access to your contacts, location or other sensitive data to protect your privacy.
The need to deny permission by default for apps to access your smartphone's microphone, camera or messages is very useful, especially to defend yourself from those illicit apps or those that may hide malware ready to infect your device. Other times, however, permissions are needed to allow the app to perform its functions. Knowing and consciously choosing which permissions to allow and which to deny can make a huge difference to your security, and there are five in particular that you need to pay attention to.
Please Don't Give Permissions: Accessibility
Accessibility encompasses a number of Android features that aid in the use of the operating system and improve the user experience, especially for those with disabilities, such as the visually impaired. Therefore, when you authorize an app to access the Accessibility data, it will be able to see everything that happens on the screen, make changes and control any function of the device just as if it were the user doing it.
Apps that need access to Accessibility are for example the Voice Assistant, which performs voice commands, or the phone.
The risk of granting this authorization is that an attacker, using for example malware, can access your bank's apps, emails and messages. To check which apps have been authorized, go to Settings and check under Accessibility.
Device Administrator: do not authorize
Becoming a device administrator is a feature that allows you to access your smartphone remotely. Remote access grants you the ability to monitor what you do with your phone, change account passwords, lock the screen, or even delete files. This kind of permission might be necessary on a company-provided smartphone for work, but it's certainly not something to grant to any app you download. To check if you're at risk go to Settings, then Apps and Notifications, open Special App Access and select Device Administration Apps.
Permissions Not to Give: Install Unknown Apps
Some apps may ask permission to download other apps anywhere, even from stores other than Google Play. When downloading an app, you have to be very careful that this item is not authorized, because the risk is that you end up with malware that downloads and installs apps ready to steal your sensitive data and violate your privacy.
Permissions not to give: Show over other apps
Show over other apps is the feature that allows an app to display windows while others are running. For example, Facebook Messenger uses this permission to show the chat icon when you're using another app. The risk in granting it is to end up with annoying unwanted banner ads or with ransomware viruses that block access to your smartphone and demand a ransom to get back to it. To avoid serious consequences, it's a good idea to check which of your downloaded apps have this permission and you can do that by going to Settings, then Apps & Notifications, Apps with special access and select Show above other apps.
Don't give permissions: reading and sending text messages
If an app asks you for permission to access text messages, be very careful. An app that contains malware and has obtained your permission could read your text messages, steal sensitive data or bank details that arrive via text message, or even send messages to subscribe to expensive paid services without your knowledge. To check, follow the path Settings, then Apps and Notifications, App and SMS permissions: you'll see all the apps that have access and you can immediately disable those at risk.
Please don't give permissions: be careful
Android offers a set of permissions that goes well beyond the four we've listed so far and a user can easily check those granted by following the paths described in the previous paragraphs. From Settings in the Apps and Notifications section you can grant or deny permissions to contacts, to see your location or in the Apps with special access section, you can deny permissions to features you didn't even know you had on your Android smartphone. The advice is to always choose carefully what permissions you grant to an app when you install it, but most importantly to perform a periodic check of what permissions you've been granted to downloaded apps and if any accounts don't add up, take immediate action to protect your security.