Does Your Computer Have a Virus? Here Are Ten Warning Signs

You can tell if your computer has a virus by looking for warning signs, such as slower performance speed, increased pop-ups, frequent crashes or freezes, reduced battery life and unfamiliar files. A computer virus is a type of malware that requires user interaction to infect your computer. Computer viruses can disguise themselves as email attachments in phishing scams, illegitimate files, altered code or pirated software.

Continue reading to learn how computers get viruses, the warning signs your computer may have one and the steps you should take if your computer is infected.

How do computers get viruses?

Your computer could get infected with a virus if you interact with certain types of malicious content.

• By clicking on malicious links or attachments, a virus could be installed on your computer and infect it without your knowledge. Most of these viruses are embedded in phishing emails, which aim to trick you into revealing personal information by opening a malicious website or file.
• While browsing the internet, you may come across an appealing advertisement, but clicking on a malvertisement – a fake ad created by a cybercriminal – could lead to your computer becoming infected with a virus. For example, if you’re online shopping and get a pop-up that says, “Your computer is infected! Scan for a virus now!,” clicking to scan for the alleged virus will actually install a virus on your computer.
• If you visit suspicious websites to download a game or stream a free movie, viruses could infect your computer, as these are illegitimate ways of accessing content. Any website offering free software, apps or media content can install viruses onto your computer to steal your data.

10 signs your computer has a virus

You can tell if your computer has a virus by looking out for warning signs, ranging from performance issues to the presence of unfamiliar apps in its library. Let’s look at 10 of the most common signs that your computer has a virus.

1. Your computer is running slower than usual

If you realize that your computer is running much slower than usual, this could be a sign that your computer is infected with a virus. While some older computers naturally run more slowly, a virus can cause your computer to perform significantly worse than usual. Since viruses consume a lot of resources, they can lead to a sudden decrease in your computer’s performance.

2. You’re noticing an increase in random pop-ups

Sometimes, pop-ups will appear while you browse certain websites to inform you about a discount. However, if you notice a sudden increase in random pop-ups while browsing the internet, it could mean your computer is infected with a virus. Pop-up ads may contain malware that, if clicked, can install on your computer and run without your knowledge. Once a virus is installed on your computer, it can steal your personal information, such as login credentials and credit card numbers. These pop-ups may appear as error messages, inappropriate images or even messages claiming your computer has a virus. No matter what these pop-ups say, avoid clicking on them to prevent viruses from being downloaded onto your computer.

3. Your computer crashes and freezes often

While running a resource-intensive program or app, your computer may crash or freeze. However, if your computer crashes or freezes frequently without any demanding program running, it could mean a virus has infected your computer. A computer virus consumes a lot of space in your files and can overload your computer’s resources.

4. There are changes to your browser homepage

If you didn’t make any changes to your browser’s homepage but notice it has switched to a different default website, your computer may be infected with a virus. Noticing any changes to your browser settings, such as its theme, privacy settings, tools, bookmarks or extensions, could mean that a virus has made these alterations.

5. Unknown programs are starting randomly

Another sign that your computer may have a virus is if unfamiliar programs or apps begin to open randomly. This strange behavior could indicate that a virus is launching programs that you don’t remember downloading or using. These programs might resemble ones you do recognize, so make sure to regularly check your apps and programs to delete anything unfamiliar or suspicious.

6. Your computer’s battery is draining quickly

Noticing that your computer’s battery is draining quickly can be a sign of a virus, especially if your computer is relatively new. When your computer’s battery life quickly drops, this could mean a virus is running in the background and is spreading to impact your computer’s systems. The more a virus spreads, the worse your computer’s battery life will be. The overall functionality of the device will degrade as well.

7. You notice unfamiliar files and folders

Similar to unknown programs appearing and running, you may also notice unfamiliar files and folders if your computer has a virus. If you discover files or folders you don’t recognize, a virus may have installed them to attempt to disguise itself as something you might overlook. Some viruses modify files on your computer to have almost identical names, blending in with the rest of your documents.

8. Your security tools are disabled

Think of all the security tools that automatically run on your computer. When your computer has a virus, you may notice that your security features have been disabled without your permission. Some viruses are designed to disable security tools, allowing them to access the rest of your computer’s data and private information. For example, if you have antivirus software installed on your computer and you notice it’s been disabled, this could mean a virus has disabled your security features. If you discover that your computer’s security tools have been disabled, turn them back on. If they become disabled again on their own, it’s a clear sign that a virus has altered your security settings.

9. There are emails you didn’t send in your sent folder

You should check your sent folder for emails you didn’t send, as this is another common sign that your computer has been infected with a virus. If you clicked on or interacted with an unsolicited email, you may have downloaded a virus onto your computer, which could give a hacker access to scam those in your contact list. A hacker may have accessed your email account and sent emails containing malware to all your contacts to continue spreading computer viruses.

10. You’re unable to access your computer or accounts

If you realize you can’t access your online accounts or your entire computer, this is a sure sign that a virus is running on your computer. You may try to log in to an online account and realize you are locked out of it. A virus could have been installed on your computer and made changes to your account’s password, or even your computer’s password.

What to do if your computer has a virus

If you learn that your computer has a virus, you should do several things immediately, including downloading antivirus software, checking for malicious applications and updating your computer’s software.

Step 1: Download antivirus software

Antivirus software can be installed on your computer to detect, stop and eliminate known viruses and malware before they infect your device. Several great options for antivirus software you can download include Malwarebytes Premium Security and McAfee Antivirus.

Step 2: Disconnect your computer from the internet

Turn off the WiFi on your computer when you realize it has been infected with a virus because this can stop the virus from spreading further. By disconnecting your computer from the internet, you can stop a cybercriminal from accessing your computer and private information by preventing the virus from spreading on your device.

Step 3: Reboot your computer in safe mode

Entering safe mode and rebooting your computer will allow you to figure out what is preventing it from functioning as it should. Safe mode is a feature that most computers have, which only launches essential programs, files and apps to troubleshoot any problematic software.

To enter safe mode on your Mac, you first have to shut it down. Once it’s shut down, press and hold the power button until the Loading startup options screen appears. Choose a boot volume, then press and hold Shift. Click Continue in Safe Mode, then wait for your computer to restart automatically. After it reboots, your computer will display Safe Boot in its menu bar to show that it is in safe mode.

For Windows users, you can enter safe mode by holding Shift and Power at the same time. Once you see the button to restart, select that and let your computer reboot. After the screen reappears, select Troubleshoot, then Advanced options and Startup Settings. Once you let your computer restart once more, hit F4 to enter safe mode.

Step 4: Check for malicious applications

No matter what kind of computer you use, you need to look for malicious applications in your library. Apple users can do this through the Activity Monitor, and Windows users can do this through the Task Manager.

For your Mac, you can access the Activity Monitor by going to Finder, Applications, the Utilities folder and then Activity Monitor. This will show you which apps or programs are taking up space and energy on your computer within the last 12 hours. If any programs or apps are running that you don’t recognize, select the app within the Activity Monitor and force quit the application.

For Windows computers, you can access the Task Manager to check for malicious apps by right-clicking the taskbar at the bottom of your screen. Select Task Manager, then More Details. This will show a list of apps and programs currently running on your computer. If any of them look suspicious, right-click them within Task Manager and hit End Task. Visit the Startup tab at the top of Task Manager, and if any apps are enabled, right-click them and select Disable. Doing this will stop any suspicious apps from running on your computer.

Step 5: Scan your computer using the antivirus software

After following the above steps, you should scan your computer using antivirus software. This will determine if any viruses exist on your computer that match the software’s database of known viruses and malware. If a match exists, the antivirus software will immediately isolate the virus from the rest of your device and delete it before it can interact and infect your computer.

Step 6: Clear your cache and update your computer

Once you’ve found and eliminated the virus from your computer, you should clear your cache and update your computer with the latest software updates. When you clear your cache, you delete any temporary data stored on your web browser, apps and computer. This is a necessary step in reducing virus infections because cybercriminals can hide viruses and malware within your browser’s cache. In most web browsers, you can clear your cache by visiting your settings and finding tabs related to your browsing history.

If you don’t already have the latest software update installed on your computer, you should update your computer to enhance its features, patch security flaws, fix bugs and increase its overall security. Having the latest software installed on your computer protects your accounts and device from viruses or malware because known vulnerabilities are fixed with each new update. If you don’t update your computer regularly, cybercriminals can exploit security flaws and install viruses more easily.

After trying all the steps above, if you know a virus remains on your computer, you will need to contact an IT professional to help remove it. Once the virus is fully removed, you should update all of your passwords as a security precaution. The quickest way to change many passwords at once is to use a password manager. With a password manager like Keeper^®, you can click on any record you want to change and make a new password using its built-in password generator. This ensures that any new password you create will be strong and unique.

Keep your computer protected against viruses

Protect your computer from viruses by recognizing the common warning signs, such as slower performance, quicker battery drainage and unfamiliar apps or programs. If you realize your computer has a virus, you must download antivirus software, reboot your computer in safe mode, check for malicious apps and scan your computer for viruses. After eliminating the virus, you should change all your passwords using a password manager like Keeper to protect your online accounts from further damage.

Start your free 30-day trial of Keeper Password Manager today to quickly change all your passwords for better protection against viruses.