How to disable installation from unknown sources on Xiaomi Redmi 9: the complete guide

Installing apps from unknown sources on Xiaomi Redmi 9 is a feature that lets you download APK-Not only do files come from the official Google Play store, but also from third-party resources, which gives you freedom of choice, but also opens the door to potential threats, such as viruses, spyware and fraudulent programs. Whether you handed over your smartphone to a child, colleague, or just want to protect your data, turning off this option becomes a critical step.

In this article, we will discuss how to completely block the installation. APK from unknown sources on Redmi 9 (including Redmi models 9A, 9C, 9T), What are the nuances in different versions MIUI (12, 13, 14), And what to do if the standard settings don't work, and you'll learn how to check which apps already have permission to install third-party files, and how to fix them. 10/11/12 shelled MIUI.

Why do I need to shut down the installation from unknown sources?

The main danger of third-party APK-The problem with the files is that Google Play Protect, the built-in virus scanning system, lacks control over the files. According to Kaspersky Lab, in 2023, more than 30 percent of Android malware was spread through third-party sources:

• 🦠 Viruses and Trojans: Files can contain hidden scripts to steal data, send it SMS to pay numbers or lock devices.
• 🕵️ Spyware: Some apps secretly collect browser history, contacts, or bank card data.
• 💸 Fraudulent programs: Fake versions of popular apps (such as WhatsApp or TikTok) may require payment for “premium features".
• 🔄 Automatic Advertising: Some of the APK in the background download banner ads or redirect to phishing sites.

Even if you are sure of the APK source (for example, downloading from the 4PDA forum), there is always the risk that the file was modified by attackers. Disabling the installation from unknown sources is like a lock on the door: it does not guarantee 100% security, but makes it much harder for scammers to do the job.

⚠️ Attention: Redmi 9 with firmware MIUI Global Some system applications (such as Mi Browser or GetApps) have default installation permissions APK. They need to be checked, too!

Where is the setting on Xiaomi Redmi 9?

Unlike “pure” Android, where the option is hidden in the security settings, on Xiaomi the path depends on the version of MIUI.

If you don't find a destination along the path, try searching in the settings (the magnifying glass icon in the upper right corner) and enter "Install unknowns" and the system will tell you the current location.

Step-by-step: how to disable APK installation on Redmi 9

Follow this algorithm to completely block the ability to install third-party files. The instructions are universal for all Redmi 9 modifications (including 9A/9C/9T) and MIUI versions.

1. Open Settings (the gear icon on the home screen or in the application menu).
2. Go to Privacy (or Security if you have MIUI for Russia).
3. Select Special Permits → Install Unknown Applications
4. You will see a list of all applications that are allowed to install APK. By default, there may be: 🌐 Mi Browser (built-in browser Xiaomi) 📁 Files (conductor) MIUI) 📥 GetApps (branded store Xiaomi) 📧 Mail or Gmail

Click on each application from the list and turn the slider to the "Off" position. Confirm the action if the system requests a password or fingerprint.

Check that all sliders are gray, which means that the APK installation is blocked for all applications.

Settings open. → Confidentiality|Checked section "Installation of unknown applications"|All sliders are translated to the "off" position."|The system does not request confirmation when installing APK-->

If you can still install APK after you turn off (for example, through ADB or Fastboot), then your device has activated developer mode. To fix this, go to Settings → About → MIUI version and click on this item 7 times. Then go back to Settings → Additional → Developer and turn off the USB Debugging option.

What to do if the settings are not saved?

Sometimes, after the installation is turned off from unknown sources, the sliders spontaneously return to the "On" position.

• 🔄 Automatic update MIUI: After the system update, some settings are reset.
• 🧩 Optimizer Conflict: The Security App Can Reset Permissions.
• 🦹 Virus activity: If the device already has malware, it can block changes.

Decisions:

1. Turn off Automatic Optimization: Go to Settings → Battery and Performance → Optimization. Turn off Automatic Optimization.
2. Reset the Security settings: Open Settings → Applications → Application Management. Find Security (or “Security”), click Storage → Clear Data.
3. Check your device for viruses: Use Kaspersky Mobile or Dr.Web Light to scan. Remove suspicious apps manually.

⚠️ Note: If after all the manipulations, the settings continue to reset, this may indicate root access (root) or modified firmware. In this case, it is recommended to perform a full reset to factory settings (Settings) → The phone. → Resetting settings).

How do I check which apps already have permission?

Even if you turned off APK installation for all applications, some of them might have been allowed earlier to make sure that they were safe.

1. Go to Settings → Privacy → Special Permissions → Install Unknown Applications.
2. If the app's name is "Allowed," it can install APKs.
3. Click on each application and turn off the permission.

Pay special attention to the following applications (they often have default resolution):

• 📂 Files (conductor) MIUI)
• 🌍 Mi Browser or Google Chrome
• 📧 Gmail or Mail
• 📥 GetApps (Xiaomi store)
• 🤖 Package Installer (system installer)

Alternative ways to protect against malicious APKs

Disabling the installation from unknown sources is only the first step.

1. Enable Google Play Protect: Open Google Play Store → click on the profile icon → Play Protect. Activate the options to Scan Your Device for Threats and Improve Malware Detection.
2. Install antivirus: Recommended apps: Kaspersky Mobile, Bitdefender, Malwarebytes. Set up regular scans (for example, once a week).
3. Disable installation from browsers: In Chrome or Mi Browser settings, disable Download Files for APK.
4. Use Child Mode: In Settings → Special Features → Children’s Mode can be limited to installing any applications.

On Xiaomi Redmi 9 with MIUI 13+, there is a hidden “Installation Lock” feature in the developer menu. To activate it, turn on Developer Mode (7 taps according to MIUI), then go to Settings → Additional → For Developers and find the option to Disable Installation from unknown sources. This will completely block the ability to install APK, even through ADB.

Frequent Mistakes and How to Avoid Them

When disabling the installation from unknown sources, users often face the following problems:

If you encounter an error not described in the table, try resetting your security settings:

1. Go to Settings → Applications → Application Management.
2. Find Security → Storage → Clear the data.
3. Reset the device.

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If you're transferring your smartphone to another person, be sure to check not only the APK installation settings, but also the list of allowed apps, and even one app with a resolution can become a loophole for viruses.

FAQ: Answers to Frequent Questions