Do you think your computer might have a virus? If so, don’t panic! In this article, we will describe the signs that your computer might be infected and go over ways to remove the virus. We will also provide tips on keeping your computer safe from viruses in the future. So don’t worry – we will help you get your computer humming along in no time!
Most modern computers have antivirus software already running, either built into the OS or bundled with other software. This may include your computer, and in that case, you may be wondering: could you still be infected with a virus? The answer is: yes, it’s possible. The three primary reasons for this:
- You have not updated your antivirus software lately (this is usually automatic but can be disabled), or the publisher is not supporting the product actively;
- A new virus that is not yet in the databases of antivirus products has infected your machine;
- You disabled your antivirus software to do something or install something, and that’s when you were infected.
Signs that your computer may be infected with a virus
Viruses and malware can affect your computer’s behavior in various ways. The creator(s) of the virus do not want you to know that your computer has been affected, so they will make deliberate attempts to hide a viral infection. However, if you experience any of the following behaviors, it could be a sign that your computer has a virus:
- Your computer is running slowly (overworked CPU or hard drive)
- You are receiving error messages that you don’t understand
- Files or programs are disappearing from your computer
- Your browser home page has changed without you changing it
- Your browser is slow or redirects you to strange websites
- You can’t visit certain websites
- There is new software on your computer that you didn’t install
- Popups appear even when you’re not browsing the Internet
- You are locked out of your computer
- Strange emails in your sent folder, or acquaintances saying they got strange/spammy email from you
- Antivirus or firewall is disabled or can’t load
Let’s take a closer look at each one of these signs:
Your computer is running slowly (overworked CPU or hard drive)
One of the most common signs of a virus is a sudden decrease in your computer’s performance. If your computer seems to be running slowly, it could be because the virus consumes valuable resources like your CPU or hard drive. If you notice that your computer’s fan is running loudly or that programs are taking longer to load, these could be signs of a virus. On Windows, you can run the Task Manager to see basic metrics like RAM usage, CPU usage, and hard disk activity (on macOS, use the Activity Monitor). If you close all programs and these numbers are still elevated, a virus may be using system resources.
You are receiving error messages that you don’t understand
Another common sign of a virus is receiving strange error messages. If you see popup windows with error messages that you don’t understand, the virus may be trying to trick you into clicking on something. The messages are constructed to look like valid system errors, but their intent is 100% malicious. Be very careful about clicking on any links or buttons in these error messages, as you could inadvertently give the virus permission to do more damage to your computer. Search the error message on your preferred search engine if you are unsure of its legitimacy.
Files or programs are disappearing from your computer
If files or programs start disappearing from your computer, the virus may have deleted them. A virus might inadvertently delete user or system files or do so to prompt action on your part, such as forcing you to reboot your computer. The virus might delete essential system files in some cases, rendering the computer unusable. If you think this has happened, it may be time to engage a professional. Missing system files can cause problems with your system and can be challenging to fix, but if you wish to try it, here are guides for Windows and macOS.
Your browser home page has changed without you changing it
One of the first signs that many people notice when their computer is infected with a virus is that their browser’s home page has changed. The virus creator wants you to see specific content every time you open your browser. If your home page has changed and you didn’t change it, this is a strong sign that your computer is infected with a virus. However, some browser addons that have otherwise legitimate uses will also change your home page to show sponsored content that can earn ad revenue for the publisher of the addon. If that’s the case, you can usually change your browser’s home page back easily enough – here’s how to do it in Chrome, Firefox, Edge, and Safari.
Your browser is slow or redirects you to strange websites
Another sign that your computer may be infected with a virus is if your browser seems to be acting strangely. If it’s running slowly or if you find that you’re being redirected to strange websites, these could be signs that the virus has hijacked your browser. In some cases, the virus might even prevent you from opening your browser at all, or it may present you with a fake error message suggesting that the Internet cannot be reached with a button or link to “fix” the problem – do not click it! Instead, check your Internet connection status in Windows or macOS.
You can’t visit certain websites
If you find that you can’t visit certain websites, the virus may have blocked them. In some cases, the virus might block websites that provide security or antivirus software so you can’t download and install a program to remove the virus. If this happens, you can try using a different browser – if the problem persists, a virus may have taken over your computer.
There is new software on your computer that you didn’t install
If you find new software or programs on your computer that you didn’t install, it’s a strong sign that your computer has been infected with a virus. These programs are usually designed to either display advertising or steal your personal information. In some cases, the virus might even have masqueraded as legitimate software to trick you into installing it. If you’re not sure whether a program is legitimate or not, you can check online to see if other people have reported it as being malicious. If you want to uninstall a program, here’s how in Windows and macOS.
You see strange popups or ads, even when not browsing the Internet
One of the most common signs of a virus is seeing strange popups or ads, especially if they start appearing when you’re not even browsing the Internet. These popups can also be generated by “adware” installed on your computer. Adware is usually not malicious, but it can be very annoying. If you see popups and ads, even when you’re not browsing the Internet, it’s a good idea to proceed on the assumption that your computer has some kind of infection.
You are locked out of your computer or specific programs or files
In some cases, a virus might lock you out of your computer or specific programs. This is usually done in an attempt to extort money from you – for example, you might see a message saying that your files have been encrypted and that you need to pay a ransom to get the key to decrypt them. If this happens, do not pay the ransom! There is no guarantee that you will get your files back, even if you do pay, and you will likely be targeted again with another demand. See the section below about ways to remove a virus / restore your computer if you find yourself in this situation.
Strange emails in your sent folder, or acquaintances saying they got weird/spammy emails from you
Another sign that your computer may have a virus is if you start seeing strange emails in your “sent” folder or if people you know start telling you they received weird/spammy emails from you. This usually happens when the virus hijacks your email account and starts sending out messages to everyone in your address book. If this happens, it’s essential to change your password as soon as possible and take whatever measures needed to lock down your email account. Contact your email provider to see if they have any specific recommendations.
Antivirus or firewall is disabled or can’t load
If your computer’s antivirus or firewall suddenly stops working, or if you can’t even load them, it’s a strong sign that your computer has been infected with a virus. This is usually done to prevent you from being able to find and remove the virus. If this happens, you should try restarting your computer in safe mode and see if you can reactivate the disabled functions. If you’re still having trouble, the virus may have deleted or corrupted essential files on your computer. In this case, you might need to recover or reinstall your operating system.
Dealing with an infected computer
If you experience any of these symptoms, it’s crucial to take action immediately to remove the virus and protect your computer from future attacks. There are a few different ways to remove a virus from your computer:
Run a virus scan with your antivirus software
This is the first step you should take when you think you might have a virus. Your antivirus software will scan your computer for any known viruses and malware and attempt to remove them. If you do not already have antivirus software installed, you can try to install one of the popular options like Avast, AVG, or MalwareBytes. Be advised that the virus on your system will most likely do everything it can to prevent you from doing this, like blocking your access to those websites or preventing the download from installing.
Restore your computer to an earlier date
If you think you recently picked up the virus, you can try restoring your computer to a date before you were infected. This will remove any programs or system files added since that date, which means you could potentially lose some changes. Here are the steps to restore your computer on Windows and macOS.
Reinstall your OS
If you can’t seem to remove the virus from your operating system, you can try reinstalling the OS. You should only reinstall from a trusted source, like an official website or an installation disc that you know is legitimate. Recent versions of both Windows and macOS allow a “clean” reinstall of the operating system without deleting user data and files, but it’s a good idea to backup your files anyway. Here’s how to reinstall Windows and macOS.
Reformat (erase/reset) your hard drive
If you cannot remove the virus using any of the other methods, you can reformat your hard drive and start from scratch with a fresh OS install – macOS calls this “erasing,” and Windows calls it “resetting,” but the outcome is essentially the same. If given the option, you should select “thorough” for the erase/reset stage, which will take longer but more effectively erases the drive. This option should remove even a stubborn virus, but it will permanently delete all of your files, so be sure to back up anything important before taking this step. Here’s how to reformat and reinstall your os in Windows and macOS.
Preventing future infections
Now that you know how to remove a virus, let’s talk about how to prevent infection in the first place. There are a few simple steps you can take to protect your computer from viruses:
Install antivirus software
This is the best way to protect your computer from viruses. Though it’s not 100% foolproof, installing and enabling antivirus software on your computer is your best defense against malicious programs. Be sure to keep your antivirus software up to date to protect you from the latest threats. Popular options for antivirus protection include Avast, AVG, and MalwareBytes.
Don’t click on suspicious links or download unknown files
This is how most people end up with viruses in the first place. Be careful about what you click on and only download files from trusted sources—only download files from websites you trust. Be especially careful with files that have a .exe extension or otherwise need to be run, as these are often used to spread viruses.
Email is one of the most common ways for viruses to spread. Be careful about which emails you open and which links you click. If you’re not sure whether an email is legitimate, don’t open it!
File-sharing programs like BitTorrent are often used to distribute pirated copies of movies, music, and software. But they can also be used to spread viruses, often via those same pirated programs. Avoid using file-sharing programs unless you have a legitimate reason to do so, and be careful about which files you download and share.
Keep your operating system and software up to date
Hackers often exploit security vulnerabilities in outdated software to infect computers with viruses. By keeping your operating system and software up to date, you can help protect your computer from these attacks. Be sure to update your software regularly, especially if you’re prompted. Many software programs have an auto-update feature that will download and install updates for you – it’s strongly recommended that you use this feature.
Don’t run programs with elevated privileges unless you know that you need to
Windows has a function called “run as administrator” that allows programs to run with increased privileges; it’s known as the “root user” or “superuser” on macOS. This is sometimes necessary for specific programs to function correctly or perform a particular operation, but viruses can abuse it. Be very careful about which programs you allow to run as administrator, and only do so when necessary.
By following these simple steps, you can help keep your computer safe from viruses. To recap: install antivirus software and keep it up to date, be careful about what you click on and download, and update your software regularly. Take these precautions to help protect your computer from malicious attacks.