How to Check for Smartphone Virus Infection | Virus Symptoms and Countermeasures

Virus and Malware threats targeting smartphones and mobile phones have been a critical issue for mobile users worldwide. Threats against mobile devices started showing its appearance around August 2010 and have been increasing year after year.

In this article, we will explain the major symptoms that appear on virus-infected smartphones, and effective measures to prevent virus attacks.

5 Smartphone Symptoms of Virus Infection

Here are 5 symptoms that can be used to check if a smartphone under virus infection.

  • Slow performance, high network consumption
  • Camera captures on its own
  • History of unknown outgoing calls
  • Unrecognized app is installed
  • Unexpected data loss

Slow performance, high communication network consumption

If you noticed a performance issue on your smartphone even there is no application running, this can be an indication that some programs are still running behind the scene.

Viruses and malicious applications are typically designed to run in the background to send identity information and network communication without being noticed by the user.

If you notice an unusual high network consumption even there is no application running or while your sleep, it can be a sign that something fishy is going on.

Camera captures on its own

If the camera captures an image or makes a capture sound on its own, there is a chance that an infected virus is causing the behaviors. Hackers can remotely command a virus to capture images and videos using the camera to spy on a user's lifestyle.

History of unknown outgoing calls

Some viruses specialize in making calls to foreign countries without permission and later request charge for a high communication fee. In some cases, the phone suddenly makes unfamiliar sound and repeatedly send out calls to unknown phone numbers over a period of time.

Unrecognized app is installed

If you notice an unrecognized application installed on your phone, it could be a sign of virus activity. YiSpencter is a type of iOS worm that will install programs and run them to use as an advertisement base. Make sure to keep track of installed programs and occasionally organize to check for unusual behaviors.

Unexpected data loss

Virus specializes in destroying or deleting data by nature. On a mobile device, data loss occur on images, emails, contact list, and many other types of information. Important data should be periodically backed up to prepare for the recovery.

Other Potential Symptoms

  • Unusual app shut down
  • Random phone reboot
  • Fast battery drain
  • Operates on its own

These symptoms may also be caused due to malfunctions, deterioration, or excessive usage of the app. If you experiment with these symptoms, we recommend performing a virus scan or take in your phone to the manufacturer for an official repair.

There are virus infection cases without symptoms

Viruses and malware can infect devices and perform malicious activities without being noticed by the user. For this reason, there are many cases that infected mobile device continues to corrupt systems and steal information while users are unaware of.

The key countermeasure for mobile threats is to maintain the security of smartphones and prevent any sort of virus infection.

Symptoms Unrelated to Smartphone Virus Infection

There are symptoms that might confuse users that their smartphone is under virus infection.

An alert message saying "Your mobile phone is under virus infection"

In some circumstances, a warning message that says "Your mobile phone is infected by virus" will unexpectedly appear on the screen. If this happens to you, do not panic.

This is a threat technique called "Scareware" which is designed to scare users to trick them into installing an actual virus. The alert message may show multiple times from a malicious application or website, but keep in mind that a legitimate application or business will not prompt an alert in such a manner.

Therefore, when you receive an alert message informing your device is under virus infection, it is important to calm down before taking any action. Especially do not download anything or make any payments. We recommend doing a research about the malicious app or website and if necessary install a antivirus application from a legitimate source.

Receiving spam mails

You may receive an unfamiliar email from a newsletter or online service. This is most likely not caused by a virus activity on your phone, but instead, the service you registered your email address might behave irregularly due to activity by unauthorized access.

Spam mails can also be sent from family, friends, or co-workers when there is a virus infection on the device that message was sent. Malware such as computer worm and Emotet are known to send out virus-contaminated emails by impersonating the user profile.

A good countermeasure is to place a spam block on the sender or update your email address. You can also report a spam incident through your email software or directly inform the person about the incident to prevent further infection spread.

Purpose of Infecting Smartphone with Virus

Hackers who create and inject smartphone viruses gain benefits from virus victims. Let's look into the main purpose of a smartphone virus and prepare for attacks.

Steal Personal Identity

User identities are hackers' favorite money-making information. Profile information such as a home address, phone number, online account, Social Security number, and location are popular items that get traded in the hacker community.

Especially credit card information and financial account passwords can directly impact victims in a financial manner.

Interception and Voyeur

Some hackers use the camera and microphone of a smartphone to spy on users' privacy. User's phone conversations and surrounding images are useful information for hackers that are looking for specific information.

Remote Control

The ability to remote control user's smartphone brings many benefits to hackers. For example, by using remote control feature hackers can register users to a malicious service, install dangerous viruses, steal information, or make expensive calls.

Using the phone as a stepping stone for crimes such as DDoS attacks and email spam sources can also be critical harm for users. There are some reports that people got mistakenly arrested even though they were also victims of hacking activity.

Ransom Demand

A type of malware called Ransomware specializes in blocking smartphone users partially or entirely from using their phones. Malware will ask for a ransom payment in exchange for releasing the locks.

A lock can be placed on the feature or the entire OS of the smartphone. In some cases, the data will be encrypted with a key making the user impossible to extract data. A good practice to prepare for attacks similar to Ransomware is to periodically backup data to external storage.

How to Check Smartphone Virus Infection

The best way to check if your smartphone is infected by the virus by using an Antivirus application.

Antivirus is specifically designed to perform a deep scan to discover any malicious program running on your smartphone. Because there are some types of viruses that might not be detected, we recommend using a result proven reliable Antivirus application released by major security organizations.

How to Prevent Virus Infection

Be aware of the following rules to prevent your smartphone from being infected with viruses.

Update and upgrade OS version

Smartphone OS updates will automatically apply the latest security patches to your device. Keep an eye on the latest OS versions or be informed about the updates by enabling the update notification feature.

Avoid accessing malicious websites

Malicious websites can harm you in a variety of ways. Some sites will try to make users download a virus-infected file, while others will attempt to submit a fake online payment to steal money from you.

These sites are typically disguised with a design from publicly known legitimate business to gain trust from you. Don't be fooled by trying to login with your account credentials, any inputted information could be sent to the hacker.

Do not download unofficial files

Hackers use a technique called Trojan virus which hides malware into an ordinarily looking file, which installs viruses upon execution. These malicious files can be uploaded in many online forums and sites with different file names.

If you encounter a free application from an unofficial source, it is most likely a Trojan virus. Only trust applications from the phone OS market place and never download files from unfamiliar sites, URLs, or email.

Disable "Unknown Sources" installation option (Android Specific)

Android phone has a setting that allows the user to install applications from an unknown source. This feature is usually used by a developer who creates personal applications or users who want to install third-party programs.

Android security setting unknown source disable

To disable this feature, go to "Setting" -> "Security" and turn off the "Unknown Sources" feature. This way whenever an application from an unknown source is about to be installed, the smartphone will alert the user before performing the installation.

Avoid connecting to an unfamiliar Wi-Fi access point

Unfamiliar Wi-Fi can potentially be a gateway to network communication exposure. There are hacking strategies that performed through custom Wi-Fi access points.

Malicious Wi-Fi access points are commonly found in public environments, such as hotels, concerts, stations, and parks. The fact that malicious Wi-Fi are typically accessible without a password can be a good way to distinguish from safe ones.


We discussed the common symptoms of virus-infected smartphone and ways to prevent from being attacked. We also looked through what are the main intentions of smartphone viruses so that we can be aware of what to secure.

The best security against smartphone virus is to not be infected. A good practice is to install an Antivirus program beforehand to protect your smartphone from any injection attacks.