How to know if you have a virus on your phone and what to do next

It's important to note that, technically speaking, phones don't really get "viruses" in the traditional sense. What most people refer to as a "virus" is usually a broader type of malicious software known as malware. However, since the term virus is commonly used when talking about phone infections, we'll use it throughout this article to keep things understandable.

In this article, we'll share how to know if you have a virus on your phone, what causes these infections, and what to do if something's not right. Whether you're using an iPhone or an Android phone, spotting the warning signs early can save you a lot of trouble and help keep your data safe.

Can iPhone and Android devices get viruses?

Yes, both iPhone and Android devices can get viruses — but the risks and methods of infection aren't the same.

Android phones are more commonly targeted because of their open nature. Unlike Apple's iOS, Android lets users install apps not only from Google Play but also from third-party stores or directly through APK files. While this gives users more control, it also increases the chance of downloading harmful apps, especially if the app looks legitimate but contains hidden malware.

iPhones, on the other hand, are generally more secure thanks to Apple's locked-down ecosystem. Most apps come through the App Store, which has strict review processes. But even that doesn't guarantee full protection. If you ever click on a shady link in a text or email, you could still get your mobile device infected with spyware or trojans.

It's also worth noting that mobile viruses often come bundled with other types of malware. A virus might replicate itself, but some threats will quietly collect your data, flood you with ads, or give hackers access to your accounts. That's why even minor signs (think strange messages, excessive data usage, or poor performance) shouldn't be ignored.

In short, no matter which mobile device you use, it's smart to stay cautious. Mobile viruses are less common than on computers, but they do happen — and they can be just as disruptive.

How do phones get viruses?

Phones can get viruses through infected apps, malicious downloads, or even from fake software updates. Most mobile infections don't happen by accident — they rely on users clicking, tapping, or downloading something that seems harmless at first.

The most common way mobile phones get viruses is through third-party apps. These are apps downloaded from outside of official stores like Google Play or the App Store. They may promise useful features or free versions of popular tools, but they can hide trojans, adware, or other cyber threats. Yes, that applies even to some apps within official stores.

Another method is phishing, which occurs when a user receives a fake message, email, or notification that looks legitimate. Such messages may ask users to click a link or download a file, which can lead to a virus infection or data theft. This type of tactic is a common way phones get infected with spyware, which secretly monitors what you do on your device.

For those loving a good work-from-a-coffee-shop moment, it's worth knowing that public Wi-Fi can also be risky. If you're connected to an unsecured network, attackers may manipulate your traffic and push harmful downloads onto your phone. And in some cases, malware can come through vulnerabilities in outdated operating systems or unsafe websites.

Understanding how to tell if you have a virus on your phone starts with knowing how infections get in. Most of them are designed to stay hidden for as long as possible.

Main types of phone infections

Viruses on phones don't always look the same. Some crash your apps or flood your screen with ads. Others work quietly in the background, stealing your data or tracking what you do. 

Below are the most common types of infections to watch out for.

• Malware is the umbrella term for all kinds of harmful software, including spyware, adware, ransomware, and trojans. These programs can slow your device down, steal your personal information, or lock you out of your files.
• Spyware runs silently and keeps track of your activity — from the websites you visit to your texts, calls, or even your location. Some versions are used for targeted surveillance, while others are aimed at stealing passwords, financial data, and other sensitive information.
• Adware bombards you with unwanted pop-ups, banners, and full-screen ads. In some cases, it also collects data about your behavior to serve even more aggressive ads later on.
• Ransomware locks your phone or encrypts your files, then demands payment to unlock them. It's rare on mobile, but not impossible, especially if you've downloaded a suspicious file or app.
• Trojans disguise themselves as useful apps or software updates. Once installed, they can give hackers remote access to your phone, steal data, or install even more malware.

Each type is different, but all of them can cause real damage. That's why it's helpful to know how to check if you have a virus on your mobile phone before things escalate.

7 signs your phone has a virus

How can you tell if your phone has a virus? One way is to watch for changes in its behavior, especially if it suddenly starts acting strangely for no clear reason. 

Seven common warning signs can help you figure out if your phone has been infected. Note that these are just things to keep in mind, and they are not definitive signs of malware.

1. Random pop-up ads or new apps

If your phone starts showing pop-ups when you're not browsing the internet — especially full-screen ads or ones that appear on the home screen — it could be a sign of adware. Some pop-ups may even urge you to download suspicious apps or updates.

To be safe, take a look at your app list. If you notice apps you didn't install or don't recognize, they might have been added by a malicious program without your knowledge.

2. Device feels physically hot

It's normal for phones to warm up while gaming or charging, but consistent overheating for no clear reason might indicate a deeper problem. Some types of viruses work silently in the background, using your phone's resources to perform tasks without your consent. This constant load can make your device feel hot to the touch, and over time, it can damage your battery or internal components.

3. Random messages are sent to your contacts

Have friends or colleagues mentioned getting strange texts, emails, or DMs from you? That's often a warning sign. Some phone viruses attempt to spread by accessing your contact list and sending out messages with malicious links. These messages may appear urgent or personal, trying to trick people into clicking — and potentially infecting their devices as well.

4. Device responds slowly

A lagging phone isn't always a virus, but if the slowdown is sudden and severe, it might be. Malware can drain processing power by running hidden processes or constantly connecting to the internet. You might notice apps freezing, typing delays, longer boot times, or general slowness, even if you haven't made any recent changes to your phone.

5. You find fraudulent charges on your accounts

Some phone infections are designed specifically to steal sensitive data, such as credit card numbers, online banking credentials, or shopping account details. If you notice unauthorized charges, strange payment notifications, or login attempts from unknown devices, it's possible that a virus is capturing your data. Don't assume it's a random error — act fast to secure your accounts.

6. Phone uses too much data

Viruses often need to send and receive information to function, which can result in a noticeable spike in your mobile data usage. If an app you barely use is suddenly consuming a large portion of your data plan, it might be misbehaving or hiding malicious activity. Some viruses also update or download additional malware without your knowledge, further increasing your data consumption in the background.

7. Battery drains quickly

Most smartphones lose battery capacity over time, but if your phone's battery suddenly starts dying much faster than usual, it could be a sign of a virus. Malicious software may be running nonstop, sending data, showing ads, or communicating with servers in the background. This excessive activity drains your battery and can make even simple tasks — like sending a message or browsing — feel slower.

How can I check if my phone has a virus?

If your phone is acting strangely, there are a few steps you can take to figure out what's going on. Knowing how to check if you have a virus on your phone can help you catch problems early — before they get worse or compromise your data.

Here's how to start:

• Review your installed apps. Look for apps you don't remember downloading. Viruses and adware often come bundled in fake or duplicate apps that seem harmless at first.
• Check data and battery usage. If a single app is using far more data or battery than usual, it could be misbehaving (or hiding something).
• Run a trusted security app. Reputable antivirus tools can scan your phone for known threats. Many will also flag suspicious behavior, even if it's not a named virus.
• Watch for overheating and poor performance. If your phone slows down or gets hot without a clear reason, something might be running in the background.
• Keep in touch with your contacts. Keep an eye if anyone has received strange messages from you — this can indicate a virus trying to spread.
• Keep an eye on financial accounts. Unfamiliar charges or login attempts could point to spyware or credential theft.

These checks can't guarantee a diagnosis, but they're a strong first step in spotting problems. If something feels off, the safest move is to treat it seriously and take action to remove the virus.

How to remove a virus from a phone

If you suspect your phone has a virus, acting quickly can help you stop the damage and protect your data. Here's how to remove a virus from a phone safely — whether you're using an Android phone or an iPhone.

1. Run a virus scan

If you're using an Android phone and have downloaded apps or files from outside the Google Play Store, running a virus scan is a good first step. Android devices are more open to third-party downloads, which also makes them more vulnerable to malicious apps. Reputable antivirus apps can help detect and remove known threats like trojans, spyware, or adware. 

For iPhone users, antivirus tools are rarely necessary. iOS is designed with a closed system that tightly controls what apps can do, making traditional infections less likely.

2. Reboot your phone in safe mode

Booting your phone in safe mode allows it to run without third-party apps, which helps you check if the problem is caused by something you installed. On Androids, you can usually enter safe mode by holding down the power button and then tapping and holding "Power off." 

On iPhones, safe mode isn't available, but you can still check for any unusual activity, particularly how apps behave in the background. If you're using iOS, see our full guide on how to check for viruses on an iPhone.

3. Remove suspicious or unfamiliar apps

Go through your list of installed apps and delete anything you don't recognize, don't use, or didn't intentionally download. If you're using Android devices and are unsure whether a specific app is malicious, look up its name online — if others have flagged it, you'll likely find reports. 

This method is one of the most effective ways to remove malware from Android devices without doing a full reset. For more details specific to Android phones, check our guide on how to remove malware from Android devices.

4. Check your Google or Apple account

Some mobile viruses attempt to sync with your cloud accounts. Visit your Google or Apple account dashboard, check which devices are connected, and sign out of any you don't recognize. Change your password while you're there, especially if you've noticed strange activity or received mobile security alerts.

5. Perform a factory reset (as a last resort)

If nothing else works and the virus keeps coming back, a factory reset can wipe your phone clean. This process will remove all apps, files, and settings, so back up your data first. Then reset your phone from the system settings menu. After restarting, reinstall apps only from trusted sources and skip anything that looks unfamiliar or too good to be true.

What else should you do if you have a virus?

Removing a virus is just one part of the process. Once your phone is clean, there are a few more steps you should take to protect your data.

1. Change your passwords

If there's even a small chance that someone accessed your accounts, change all your important passwords, especially for email, banking, and cloud storage. Use strong, unique passwords for each account, and consider enabling two-factor authentication for an extra layer of protection.

2. Review your account activity

Check your email, social media, and financial accounts for any unusual activity, such as unknown logins, new devices, or messages you didn't send. If anything looks suspicious, follow up with the service provider immediately.

3. Let your contacts know

If the virus sent messages from your phone, it's a good idea to warn the people who may have received them. Let them know not to click any links and to delete the messages.

4. Back up your data

Once you're confident your phone is clean, create a secure backup of your important files, photos, and contacts. This extra security measure ensures that if something goes wrong later, you won't lose everything.

Tips to protect your phone from viruses

Once you've removed a virus — or better yet, before anything goes wrong — there are a few simple habits that can make your phone much harder to infect.

1. Stick to official app stores

Only download apps from the Google Play Store or the Apple App Store. These platforms have security checks in place to catch malicious apps before they reach users. Avoid third-party stores or APKs unless you trust the source completely.

2. Check app permissions

Some malicious apps request far more access than they need. Before installing anything, check which permissions the app wants, like access to your microphone, contacts, or location. If the permissions seem excessive, it's best to skip that app.

3. Keep your software updated

Updates often patch security flaws that hackers rely on. That includes both your phone's operating system and individual apps. Enabling automatic updates is a simple way to stay protected.

4. Use antivirus software

Security apps can help prevent infections. Many offer real-time scanning, website filters, and warnings about risky downloads.

5. Avoid public Wi-Fi for sensitive tasks

Open networks can be easy targets for attackers. If you have to use public Wi-Fi, avoid entering passwords or payment details, or consider using a VPN to encrypt your connection.

6. Don't click suspicious links

Whether it's a text from an unknown number or a strange message on social media, don't tap any links unless you're sure they're safe. If it looks weird, it probably is.

Good security habits go a long way and don't take much effort. A little caution can save you from major headaches later.

7. Use cybersecurity tools to improve your online privacy and security

Lastly, don't forget to use cybersecurity tools that will ensure you stay safe on your mobile device. While a VPN doesn't directly protect your phone from viruses, it can help to improve your overall security.

For instance, Threat Protection is a powerful cybersecurity feature integrated directly into the NordVPN app. It helps keep you safe by warning you away from malicious websites, blocking intrusive ads, and stopping web trackers.