Your Android phone can show unusual behavior for many reasons, but some changes may indicate that an unwanted or malicious app has been installed. Persistent pop-ups, unexpected redirects, unfamiliar apps, unusual battery or data usage, and changes you did not make yourself can all be reasons to investigate.

Android includes built-in security features such as Google Play Protect, which checks apps and devices for potentially harmful software and can warn about, disable, or remove harmful apps. However, no single security feature should replace careful app installation and permission practices.

Android malware does not always make your phone obviously unusable. Some threats can operate quietly in the background, while others use suspicious permissions, fake apps, deceptive screens, or other techniques to access information. For example, RemControl Android malware is a banking focused Android threat that uses advanced capabilities to interact with infected devices.

This guide explains the common signs of Android malware, how to check your phone, and what to do if you suspect an infection.

What Is Android Malware?

Android malware is malicious or unwanted software designed to perform actions that can compromise your device, data, privacy, accounts, or finances.

Different types of Android malware can behave differently. Some may display unwanted advertisements, while others can attempt to steal credentials, monitor activity, abuse permissions, or gain control over parts of the device.

Examples include:

  • Banking trojans
  • Spyware
  • Adware
  • Remote access malware
  • Credential-stealing malware
  • Malicious apps disguised as legitimate software

Recent Android threats have also demonstrated why users should pay attention to powerful permissions. For example, the RemControl Android banking trojan documented by Group-IB uses techniques involving Accessibility Services and fake banking interfaces.

Read more about the specific threat in our guide to: RemControl Android Malware: What It Is and How to Stay Safe.

10 Signs Your Android Phone May Have Malware

A single unusual symptom does not necessarily mean your phone has malware. Look for multiple unexplained changes, especially if they appeared after installing an unfamiliar application.

1. Persistent Pop-Up Ads

Unexpected advertisements that continue appearing outside the app where you normally see ads can be a warning sign.

For example, you may see:

  • Pop-ups on the home screen
  • Unexpected browser windows
  • Ads appearing when no app is open
  • Fake virus warnings
  • Notifications asking you to install an unknown app

Google lists persistent pop-ups and unwanted messages as possible signs of unsafe software.

2. Your Phone Suddenly Becomes Very Slow

Malicious software can consume processor resources or operate in the background.

If your phone suddenly becomes much slower without an obvious explanation, investigate:

  • Recently installed apps
  • Background activity
  • Available storage
  • Battery usage
  • System updates
  • Security warnings

Slow performance alone does not prove malware. Older hardware, insufficient storage, software bugs, and normal background processes can also cause performance problems.

3. Battery Drains Faster Than Normal

Unexpected background activity can increase battery consumption.

If your battery suddenly starts draining much faster than usual, check which applications are using the most power.

Look for applications that:

  • You rarely use
  • You don’t remember installing
  • Run unusually often in the background
  • Have unexpectedly high battery usage

Again, battery drain is a warning sign to investigate rather than proof of infection.

4. Mobile Data Usage Suddenly Increases

Some malicious applications communicate with remote servers or transfer information from a device.

An unexplained increase in mobile data usage can therefore be worth investigating.

Check your Android settings for apps with unusually high data consumption.

If one unfamiliar application is responsible for a significant amount of background data, investigate it before continuing to use it.

5. You See Apps You Don’t Recognize

Check your installed applications regularly.

Be cautious if you find an app that:

  • You don’t remember installing
  • Has a suspicious name
  • Uses an unfamiliar icon
  • Appeared after installing another APK
  • Requests permissions that don’t match its purpose

Google recommends removing apps that you don’t need, don’t trust, or did not get from Google Play when investigating possible malware.

6. Your Browser Opens Unexpected Websites

Unexpected browser behavior can be another warning sign.

You may notice:

  • New tabs opening by themselves
  • Unwanted redirects
  • An unfamiliar homepage
  • Search results being redirected
  • Repeated fake virus warnings

Google lists unwanted redirects and browser changes among possible indicators of unsafe software.

Before assuming malware, also check whether a browser extension, notification permission, or recently installed app caused the behavior.

7. Unusual Messages Are Sent From Your Accounts

If friends or contacts tell you that they received messages from your account that you didn’t send, investigate immediately.

This could be caused by:

  • A compromised account
  • A malicious application
  • Stolen credentials
  • A messaging app problem
  • Someone gaining access to your account

Check your account security settings and review active sessions.

8. You Receive Unexpected Security Warnings

Don’t automatically dismiss security alerts.

Android and Google services can display warnings about potentially harmful applications or other security risks.

Google Play Protect checks apps installed from Google Play as well as apps obtained from other sources. It can warn users about harmful applications and may disable or remove them.

If you receive a Play Protect warning, investigate the identified application instead of simply dismissing the notification.

9. An App Requests Suspicious Permissions

Permissions deserve particular attention.

A simple application requesting access to sensitive device capabilities without an understandable reason should be investigated.

Be particularly careful with applications requesting powerful capabilities involving:

  • Accessibility
  • SMS
  • Notifications
  • Contacts
  • Microphone
  • Camera
  • Location
  • Screen-related access

Accessibility Services are legitimate Android functionality, but they can provide significant control over device interaction. Google’s developer guidance places specific requirements around applications using Accessibility Services.

10. Your Phone Behaves Differently After Installing an APK

Think about when the problem started.

If unusual behavior appeared shortly after installing an APK from a website, advertisement, message or other unofficial source, that application deserves immediate attention.

Google recommends getting apps from Google Play where possible and notes that Play Protect checks potentially harmful applications.

These symptoms do not always mean that your phone has malware, but several unusual changes happening together deserve attention. Google identifies issues such as persistent pop ups, unexpected redirects, unwanted software, unusual device behavior, and other changes as possible signs of unsafe software. You can review Google’s malware removal guidance for additional signs and recommended troubleshooting steps.

How to Check Your Android Phone for Malware

If you notice several warning signs, don’t panic.

Start with the built-in security tools on your phone.

Step 1: Run Google Play Protect

Open:

Google Play Store → Profile icon → Play Protect

Then check the device for harmful applications.

Google says Play Protect periodically scans devices and can warn users, disable harmful apps, or remove them when a harmful application is detected.

Keep Play Protect enabled unless you have a specific reason to change the setting.

The first step is to check your device with Google Play Protect. It automatically checks apps for potentially harmful behavior and can warn you about unsafe applications. Google recommends keeping Play Protect enabled because it can also check apps installed from sources outside Google Play.

Step 2: Check Recently Installed Apps

Open your Android app settings and review applications installed around the time the unusual behavior started.

Pay particular attention to apps you don’t recognize.

If you find a suspicious application, don’t open it unnecessarily.

Step 3: Review App Permissions

Open your phone’s security, privacy, or app-permission settings.

The exact menu can differ between Android versions and manufacturers.

Look for applications with access that doesn’t make sense for what the app is supposed to do.

For example, a basic utility app requesting extensive access to device functionality deserves closer inspection.

Review the permissions given to recently installed or unfamiliar applications. Pay particular attention to permissions that appear unrelated to an app’s main purpose. Android’s AccessibilityService framework can provide applications with powerful capabilities to interact with a device, so unexpected accessibility access should be reviewed carefully.

Step 4: Check Android Security Updates

Make sure your device is running available Android security updates.

On many current Android devices, you can find update information through:

Settings → Security & privacy → System & updates

The exact menu can vary by manufacturer and Android version.

Google recommends keeping Android and security updates current when available.

Step 5: Check Security and Privacy Alerts

On supported Android versions, open:

Settings → Security & privacy

Android can display security alerts and recommendations in this area.

Google notes that the exact organization of these settings varies between Android versions.

What Should You Do If You Find Malware?

If Google Play Protect or another trusted security tool identifies a harmful application, follow the recommended removal steps.

For an unfamiliar application:

  1. Stop interacting with it.
  2. Review its permissions.
  3. Uninstall it if it can be safely removed.
  4. Run another Play Protect scan.
  5. Install available Android security updates.
  6. Review important account security settings.
  7. Check financial accounts if banking information may have been exposed.

If the application cannot be removed normally or the phone continues showing signs of compromise, Google recommends considering a device reset or contacting the device manufacturer for assistance.

What If the Malware Has Access to Your Banking Information?

Treat this as a financial security issue rather than only a phone problem.

If you entered banking credentials, card information, PINs, or verification information into a suspicious application or fake banking screen:

  1. Contact your bank through its official channel.
  2. Use a trusted device when changing important credentials.
  3. Review recent transactions.
  4. Ask your bank what additional security steps are appropriate.
  5. Monitor your accounts for unusual activity.

Do not contact your bank through a phone number or link supplied by a suspicious application.

How to Prevent Android Malware

Preventing malware is generally easier than dealing with an infected device.

Download Apps From Trusted Sources

Google recommends downloading apps from Google Play where possible.

Be particularly cautious with APK files downloaded from unfamiliar websites.

Keep Google Play Protect Enabled

Google Play Protect is designed to scan applications and devices for potentially harmful software.

It can also check applications installed from sources outside Google Play.

Keep Android Updated

Install available Android security and system updates.

Updates can address known security issues and improve device protection.

Review Permissions

Don’t automatically approve every permission request.

Consider whether the requested access makes sense for the application’s purpose.

Avoid Suspicious Links

Be careful with links received through:

  • SMS
  • Email
  • Messaging apps
  • Social media
  • Pop-up advertisements
  • Unknown websites

A link that asks you to install an APK or disable a security feature deserves extra caution.

Don’t Disable Security Features to Install an App

Be suspicious if an application or website tells you to turn off Google Play Protect or another security protection before installation.

Google specifically warns against applications that attempt to undermine Play Protect or persuade users to disable security protections.

Can a Factory Reset Remove Android Malware?

A factory reset can be part of the response when malware cannot be removed normally, but it should not be your first reaction to every unusual phone behavior.

Before resetting:

  • Back up important personal data carefully.
  • Make sure you know your account credentials.
  • Contact your bank if financial information may have been exposed.
  • Check whether your manufacturer provides specific malware-removal guidance.
  • Install system updates after resetting the device.

A factory reset removes data and applications from the device, but account credentials or information already exposed to an attacker may require separate action.

Is Every Slow or Hot Android Phone Infected?

No.

Performance problems, overheating, battery drain, storage shortages, aging batteries, system updates and poorly optimized applications can all cause similar symptoms.

The strongest warning comes from a combination of unexplained symptoms, particularly when they begin after installing an unfamiliar application.

Look at the timing, installed apps, permissions, security alerts and account activity before concluding that malware is responsible.

Frequently Asked Questions

How can I tell if my Android phone has malware?

Look for multiple unexplained symptoms such as persistent pop-ups, unexpected redirects, unfamiliar applications, unusual battery or data usage, security warnings, or messages being sent without your knowledge. These signs do not prove malware on their own, so use Play Protect and review installed apps and permissions.

Does Android have a built-in malware scanner?

Yes. Google Play Protect is built into supported Android environments and checks apps and devices for potentially harmful software. It can warn users and may disable or remove harmful applications.

Can malware drain an Android phone battery?

It can, particularly if malicious software is running processes in the background. However, battery drain can have many other causes, so it should be treated as a reason to investigate rather than proof of malware.

Can malware steal banking information from an Android phone?

Some Android malware is specifically designed to target financial information. Banking trojans can use techniques such as phishing overlays, screen monitoring or abuse of accessibility capabilities. RemControl is one recently documented example of an Android banking trojan using these techniques.

Can Google Play Protect remove malware?

Google says Play Protect can warn users about potentially harmful apps and may disable or remove harmful applications when detected.

Should I delete an app if I don’t recognize it?

An unfamiliar app deserves investigation, but don’t assume every unknown app is malicious. Some system or manufacturer applications may not be familiar to users. Check the app’s name, developer, installation date, permissions and source before removing it.

What should I do if malware has accessed my bank account?

Contact your bank through its official channel immediately, review recent transactions, and change important credentials from a trusted device. Follow any additional security instructions provided by your bank.

Can a factory reset remove Android malware?

A factory reset can help when malware cannot be removed normally, but it should be treated as a more significant recovery step. Back up important information carefully and address potentially exposed accounts or credentials separately.

Final Takeaway

A slow phone, battery drain or an unexpected pop-up does not automatically mean your Android device has malware. However, several unexplained symptoms appearing together deserve investigation.

Start with Google Play Protect, review recently installed applications, check permissions, install available security updates and investigate unusual account activity.

Most importantly, be careful about where you download apps and what permissions you grant them. If a suspicious application has already been installed, act quickly and treat any potentially exposed financial or account information as a separate security concern.

For a specific example of how Android banking malware can abuse device permissions and fake banking interfaces, see the TechZest guide to RemControl Android Malware.