Android accounts for nearly 73% of the global smartphone market, which makes it the most targeted mobile operating system by a wide margin. That scale is a direct incentive for attackers: more devices means more credentials, banking sessions, and personal data to target.
Android's built-in security protections handle the majority of everyday threats without any action on your part. But threat data from the first half of 2025 shows a 29% rise in attacks on Android smartphones, which raises the question of whether built-in protection alone is enough or if you need antivirus for Android.
What you need to know:
- Android includes several layers of built-in security, including app sandboxing, a built-in app scanner, and a runtime permission system.
- Built-in features stop many common threats, but they can’t block everything, particularly apps downloaded outside the official app store.
- Studies recorded more than 33 million attacks on Android smartphones in 2024, with banking Trojan attacks nearly tripling.
- An antivirus app adds detection capabilities that operate across install sources, browser activity, and network connections, not just the official app store.
- Older Android devices that no longer receive security patches carry a higher level of risk and benefit most from additional protection.
- Good security habits, regular operating system updates, and a reputable antivirus app together provide the most reliable defense.
How secure are Android phones by default?
Android phones are more secure out of the box than most users realize. The operating system runs several protections automatically, and for everyday use they handle the majority of common threats without any action on your part.
Because Android runs on open-source code and commands the largest mobile market share, it draws more attacker attention than any other mobile platform. The operating system responds to that pressure with several protections that run automatically.
That said, built-in security has limitations. It works best when you only download apps from the official app store, keep your device updated, and review app permissions carefully. Step outside those habits and your device becomes vulnerable.
What protects Android phones out of the box?
Out of the box, Androids are protected by four core security mechanisms: app sandboxing, Google Play Protect, runtime permissions and monthly security updates. They work together to limit what any one app can do.
App sandboxing is the foundation. This means that every app on Android runs in its own isolated environment. The Android Open Source Project assigns each application a unique user ID, and prevents it from reading or writing data from another app. For example, a photo editor can’t reach your banking app's files, nor can a game access your messages.This separation is built into the core of the operating system, so it works even if an app developer makes a mistake or intentionally attempts to insert a virus.
Android's built-in app scanner checks apps when you install them and continues to scan them periodically after installation. It compares apps against known malware signatures, and flags suspicious permission patterns. It can also detect apps that alter their behavior after passing initial review.
Runtime permissions mean each app has to ask for access to sensitive data at the moment they actually need it, rather than having it granted automatically on installation. You choose whether to allow an app to use your microphone, location, or contacts, and you can revoke those permissions at any time.
Monthly security patches address vulnerabilities in Android's core code. Manufacturers and carriers distribute these updates to keep the operating system protected against newly discovered weaknesses.
Where built-in Android security reaches its limits
Android's built-in protections work within a specific scope: apps installed through the official store, on a device that reached you clean, facing threats that behave maliciously from the start. Any deviation from this and the protections become less reliable.
The first gap is pre-installation. Some devices sold through unverified resellers arrive with malware already embedded at the firmware level. No scanner can catch a threat that exists before the device ever connects to the internet.
The second is sideloading. Installing apps from outside the official store bypasses Android's built-in screening entirely. More than 95% of the malware families that target banking credentials arrive this way. This means that most financial malware on Android is effectively self-installed. Once in place, sandboxing limits what a malicious app can do, but it can’t remove it.
The third is the browser. Phishing links in messages, emails, and social platforms operate entirely outside app-based screening. A fake login page looks identical to the real one, and no store-level check runs when you tap a link.
Do Android phones need antivirus?
An antivirus app covers the threats that Android's built-in defenses can’t: apps from outside the official store, malicious links in the browser, and malware that hides its behavior until after installation.
Why built-in Android security is not always enough
Built-in security does not stop everything. The gap is visible in the numbers.
Key stastitics.png alt=Android threat statistics showing 33 million attacks and a 196% rise in banking Trojans in 2024
A mobile malware report for 2024 recorded more than 33 million attacks on Android smartphone users globally. Banking Trojan attacks specifically jumped from 420,000 cases in 2023 to 1,242,000 in 2024, a 196% increase in a single year.
Trojans arrive disguised as utilities, modified popular apps, or even apps that passed through official store review before their malicious update landed.
Malware families like Triada go further. Triada is a backdoor-style Trojan capable of downloading and executing additional modules after installation, effectively turning an infected device into a platform for whatever the attacker wants to run next. In early 2025, researchers found Triada pre-loaded on fake versions of popular smartphones sold through unverified channels, with attackers estimated to have stolen over $270,000 in cryptocurrency before the campaign was identified.
Spyware presents a different problem. It often requests only the permissions it genuinely needs for its stated purpose, such as microphone access for a voice recorder app, then uses those permissions to collect data the user never intended to share.
How antivirus adds an extra layer of protection
A dedicated security app as Kaspersky Premium catches threats at the point of installation, before a page loads, and during runtime. These three moments are where Android's built-in scanner either has no visibility or relies on your judgment.
It scans apps from all install sources, including downloads that Android’s built-in protections may treat differently. Once an app is running, it monitors behavior for patterns that match known malware, which is something the built-in scanner can’t do after installation is complete. When an app requests permissions, it can flag requests that look suspicious given the app's stated purpose, rather than leaving that call to you.
Full protection for your Android device
Kaspersky Mobile Security detects threats across all install sources, scans links before they load, and monitors app behavior in real time. It covers your phone and tablet on a single license.
Try Kaspersky Mobile SecurityHow do Android phones get infected in everyday use?
Android phones get infected most often through ordinary user actions. These include installing an app from an untrusted source, tapping a link in a message, or downloading a file from an unfamiliar site.
What everyday actions expose your phone to threats?
The four most common routes are apps installed outside the official store, links in unsolicited messages, ads that trigger automatic downloads, and unsecured Wi-Fi networks that expose unencrypted connections to anyone on the same network.
Many Android infections begin with downloads from unfamiliar websites or links shared through messages and ads. The lure is usually a free version of a paid app: something that looks legitimate and installs without warning.
Clicking links in SMS messages or messaging apps is the second major route. Ransomware and banking malware are frequently distributed this way. The message appears to come from a courier, a bank, or a government body. The link leads to a page that either installs a malicious APK or harvests login credentials directly.
Interacting with malicious ads is less obvious. Some ad networks display ads that redirect to pages triggering automatic APK downloads when loaded, without any further taps required.
Connecting to unsecured Wi-Fi networks creates a different exposure. A device on a public network can be observed by anyone else on the same network, and man-in-the-middle attacks targeting unencrypted connections are a documented technique for credential theft.
Why trusted sources can still introduce risks
The official app store is significantly safer than unregulated download sites, but it’s not risk-free.
Even apps downloaded from trusted sources can become risky if they request unnecessary permissions or change behavior after installation. In 2024, researchers detected the SparkCat Trojan inside both major mobile app stores, where it had remained undetected for a period before being flagged and removed, only to reappear in early 2026. It targeted cryptocurrency wallet data.
App permissions are another path. An app legitimately installed through the official store can still request permissions that give it access to sensitive data. Before you tap Allow, check what permissions it’s requesting. A flashlight app asking for contacts access, or a calculator requesting location data, deserves a second look.
What are the signs your Android phone may be infected?
Signs of an infected Android phone include unexplained battery drain, unexpected data usage, persistent pop-ups, unknown apps appearing in your list, and slow performance or overheating.
What unusual behavior should you watch for?
The easiest signs to miss are the passive ones: data uploading in the background, permissions being used when you're not actively in an app, or browser behavior changing without an obvious cause. Most people notice the battery, but it's usually not where the infection started.
If your data usage has spiked without a change in your habits, an app may be transmitting information in the background. Banking Trojans and spyware routinely send stolen credentials and personal data to remote servers.
Persistent pop-ups or browser redirects that appear even when you are not actively using a browser often indicate adware or a compromised app with display permissions.
Unknown apps appearing in your list that you definitely didn't install point to a more serious compromise. Some malware families download and install additional components after their initial installation. The Triada backdoor operates exactly this way.
What should you do if your phone is infected?
Run a full scan with a reputable security app, remove any apps you did not install, update Android and all your apps, then change passwords for any account you accessed on the device.
A full scan with a security app will identify known malicious apps and give you a direct path to removing them.
Remove any apps you did not install or no longer recognize. Check your app list carefully: some malware disguises itself under names that look like system utilities.
Run any available Android updates, and check that all your apps are up to date. Security patches for the operating system and individual apps close the vulnerabilities that some malware exploits to persist after initial detection.
Change passwords for accounts you accessed on the device. If spyware was present, credentials entered during the infection period may have been captured.
If the above steps don’t resolve the problem, a factory reset will clear malicious software that has embedded itself deeply enough to survive app removal. Back up contacts and photos first, then restore only apps from the official app store rather than from a backup.
How can you keep your Android phone secure in daily use?
In most cases, keeping your Android phone secure comes down to combining safe habits with additional protection against modern threats.
What simple habits make the biggest difference?
Four habits cover the majority of risk:
- Keep Android updated,
- Download apps only from trusted sources,
- Check permissions before granting them, and
- Avoid tapping links in unsolicited messages.
Set Android to update automatically if your device supports it. Delaying patches keeps known vulnerabilities open indefinitely.
Download apps only from the official app store, or from a source you have specifically verified. When you do install from the official store, read the reviews. App reviews frequently surface malicious behavior before official detection catches up.
Check permissions before granting them. When an app requests access to your contacts, location, microphone, or camera, ask whether that access is required for the app's stated purpose. A navigation app needs location. A wallpaper app does not.
Avoid clicking links in unsolicited messages, even from numbers you recognize. Messaging-based phishing works because attackers can spoof sender information. If a message urges immediate action, a login, a payment, or an update, navigate directly to the service rather than following the link.
Use strong, unique passwords for accounts you access on your phone, and enable two-factor authentication where it is available. If credentials are stolen, two-factor authentication prevents an attacker from using them without also having access to your device.
Review your installed apps periodically. Remove anything you no longer use. Dormant apps with permissions granted months ago remain a potential exposure even if you never open them again.
How does antivirus fit into your overall protection?
Antivirus helps detect threats that may appear during everyday smartphone use, including unsafe downloads, malicious links, and suspicious app activity.
An antivirus app provides continuous monitoring rather than a one-time check. It scans apps as they install, checks URLs before pages load, and watches running processes for behavior that matches known threat patterns.
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FAQ
How do I clean my Android phone from viruses for free?
Start by running a full scan with a reputable antivirus app and removing any flagged threats. If you want deeper protection, you can try the free 30-day trial of Kaspersky Premium to check your Android phone for malware, unsafe apps, and suspicious links.
Does antivirus slow down Android phones?
No, modern antivirus apps for Android run in the background without a noticeable impact on performance. Active scanning happens when you install a new app or access a new URL, so processor use is brief. Continuous background monitoring uses minimal resources compared to most streaming or social media apps.
Do I need antivirus on an old Android phone?
Yes, an old phone that no longer receives security patches carries unaddressed vulnerabilities indefinitely. An antivirus app detects known malware and blocks malicious links, reducing the practical risk of everyday activities like mobile banking and browsing.
How often should I scan my Android phone for threats?
Most antivirus apps scan continuously, so no fixed schedule is needed. Run a manual scan after installing an app from outside the official store, if your phone starts behaving unusually, or after connecting to an unfamiliar public network.
