Galaxy device slows down, freezes, or displays ads after installing third-party apps
If your Galaxy device becomes slow, freezes, or shows unwanted ads after installing third-party apps, check for suspicious or unauthorised apps. Certain apps may display fake alerts like "Your phone is slow" or "Battery is draining fast" to trick you into downloading more apps. If your device becomes slow or shows unwanted ads after installing third-party apps, check for suspicious apps and avoid installing unknown sources in the future.
How to fix slow performance, freezing, or ads after installing third-party apps
Without installing additional apps, you can use Device care to free up storage, close background apps, check unusual battery usage, and scan for malware. This feature keeps your Galaxy device safe and optimised.
If you suspect a malicious app, use Device care to scan your phone for threats. It automatically detects harmful behaviour and allows you to remove risky apps immediately.
Note: When Device care detects apps that trigger unwanted notifications, they are automatically placed in deep sleep mode, and you can manually delete them afterwards.
1. Handle malicious apps through Device care notification
Device care automatically scans for malicious apps every 12 hours and limits them by switching them to deep sleep mode. Depending on the time of the notification, the way to check or delete apps may vary. Refer to the instructions below.
00:00 – 05:59 notifications
When the notification appears during this time, apps are switched to deep sleep mode automatically.
You can check these apps directly from the notification.
Step 1. Tap Device care notification.
Step 2. View the detected malicious apps in Deep sleeping apps.
12:00 – 17:59 notifications
When the notification appears during this period, you can delete the detected apps immediately.
Step 1. Tap Device care notification.
Step 2. View Apps to review and tap Uninstall.
Step 3. Tap OK.
Note: The notification may appear on Galaxy devices running Android 11/12/13/14/15.
2. Check malicious apps in deep sleep mode
Device care scans your device every 12 hours to detect malicious apps and automatically limits their activity by switching them into deep sleep mode.
Step 1. Tap Settings.
Step 2. Select Device care.
Step 3. Select Battery.
Step 4. Select Background usage limits.
Step 5. View Deep sleeping apps.
3. Run app security diagnosis
Device care scans your device every 12 hours to detect malicious apps and automatically limits their activity by switching them into deep sleep mode.
Step 1. Tap Settings.
Step 2. Select Device care.
Step 3. Select Diagnostics.
Step 4. Select App safety Diagnostics.
Step 5. View Apps to review and tap Uninstall.
Step 6. Tap OK.
Note:
- Malicious apps can be viewed only after Device care has put them into deep sleep mode.
- For accurate diagnosis, connect to Wi-Fi and restart your device before running the scan.
4. Delete malicious apps
If your Galaxy device still displays ads or operates abnormally without any Device care alert, remove unused or suspicious apps manually.
Step 1. Tap Settings.
Step 2. Select Apps.
Step 3. Select the app.
Step 4. Tap the Uninstall button.
Note: Some apps may not appear on the Apps screen but can be found under Settings > Apps.
Prevent and block security threats automatically
The Auto Blocker feature protects your Galaxy device from security risks, suspicious activities, and privacy threats. When turned on, it blocks apps downloaded from unverified sources outside the Play Store or Galaxy Store.
Step 1. Tap Settings.
Step 2. Select Security and privacy.
Step 3. Turn On Auto Blocker.
Refer to the related content below to learn more about the Auto Blocker feature.
Protect your Galaxy phone with the Auto Blocker feature guide
Note: Menu names, paths, and screen layouts may vary depending on your device model, software, or app version.
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