10 Best Antivirus Software 2025

The main goal of a computer virus is to get into a computer. When the virus infects the system, it attaches itself to a host such as a file, document, or program that is not immediately visible to the user. A virus can get into a computer through many different ways including downloading files from unreliable websites or links sent to your inbox by an unknown sender. Depending on the type, some viruses will maintain a dormant mode in your system until the user activates the code. This code is often triggered by specific actions. This means that the virus will not show any signs that it has infiltrated the computer. The user is not aware that when they perform a certain action, such as opening a file or program, the virus gets activated and starts to spread through the machine. Once this occurs, the user remains vulnerable to different kinds of attacks which could make the computer useless. Since viruses are designed to spread from one computer to another, computers connected through a network are placed in danger when one unit gets infected. When a user unintentionally downloads an unknown file or clicks on an unknown link, all the computers connected to the same network are at risk of getting the virus. When the user opens up the file, the virus gets activated and the code is put into action. The effects of different types of virus will also vary. While there are some viruses that are harmless and were made just to bring amusement to the creators, other types of viruses are often created to inflict disastrous effects on the user’s computer from stealing passwords to erasing all your data and completely damaging the hard disk. Here is a list of some of the common functions of computer viruses:

• Making a log of the user’s keystrokes
• Corrupting user’s files
• Viewing the user’s data
• Stealing passwords
• Spamming contacts through email
• Spamming social media accounts
• Taking over the machine

A common reminder when surfing the internet is to never click on links from sources you do not trust. If you want to avoid your computer getting infected with a virus, visiting unreliable and unsecured websites is the number one thing to avoid. This is one of the fastest ways that a virus spreads around since it takes just one second for a user to click a link. These links are often found in the form of:

• Spam email attachments
• SMS attachments
• App downloads
• Social media scams
• Download links from websites
• Sharable funny images
• Video files
• Audio files
• Online greeting cards

When you’re browsing the internet, always be wary of suspicious messages, attachments, links, and files. If you do not trust the sender or the source of the content, then it’s better to stay away from it. Do not download files from unsecured websites and from emails addresses that are not in your contact list.

If you accidentally click or download an infected link or file, the virus will be let loose onto your device’s system. If you fall victim to a particularly nasty one, the virus could also send messages on behalf of the user to compel others to download the infected file or click on the infected link.

You might be thinking, “if technology is constantly getting better and better, shouldn’t we be able to get rid of viruses?” As technology develops, computer viruses have also become stealthier and more advanced. There are some viruses that make it hard for computers to detect or identify them as a virus.

There are several different kinds of computer viruses in existence. When talking about computer viruses, we also need to talk about malware, which is the more general term for all kinds of malicious software designed to harm a system or the user.

1. Resident Virus

A resident virus is a general term that refers to any virus that infects the memory of the computer system or interferes with the functions and operations of the system. This type of virus is executed any time when the user loads the operating system.

2. Direct Action Virus

Direct action is a type of virus that only comes to action when the user executes the specific file containing the virus. Otherwise, the virus will remain dormant.

3. Multipartite Virus

The multipartite virus spreads and infects computers in many different ways. It is capable of infecting program files as well as system sectors. It can also perform a range of actions that are beyond the control of the user.

4. File Injector Virus

Also known as a file infecting virus, a file injector virus is among the most common kinds of computer viruses. The code is commonly inserted into executable files. When this is launched, it slows the system down and causes irreversible damage to the infected files.

5. Browser Hijacker Virus

This virus type takes over certain functions of the web browser and often redirects the user to a website that they have no intention of visiting.

6. Web Scripting Virus

A web scripting virus is found in the code of web pages. The virus gets launched when you visit a website with an infected code.

7. Polymorphic

This type of virus changes its own code every time it is released when the user executes the infected file. This allows it to go undetected.

8. Macro Virus

A macro virus is written in the same language used to create software applications. This type of virus is normally spread as an email attachment.

9. Boot Sector

This virus is activated when you start up or boot your computer. A common way that the virus spreads is when an infected USB drive is plugged into the computer.

10. Network Virus

A network virus can replicate itself and spread to other computers that are connected to the same network.

These are just some of the current types of viruses that can be detected by leading antivirus brands. However, new types of computer viruses are being designed as you read this article. When you’re choosing software to protect your computer, it’s important to find one that can adapt just like a virus does.

A lot of times people interchangeably use malware and virus. Although you could say that the two are similar, technically they are different. The term malware is used to refer to any malicious software. A virus is a type of malware that has the ability to self-replicate the code similar to a virus in the medical world.

A virus is specifically created with a certain goal in mind, and that is to spread itself, encrypt and delete files, modify applications or disable specific functions of the system. Meanwhile, malware can be designed with a different purpose in mind including stealing credit card information and other financial details, tricking the user to input their personal information to be used for identity theft, taking control of all the computers connected on a single network, or infecting computers in order to mine cryptocurrency such as bitcoin.

Although there are several kinds of malware out there, the most commonly found in computers is the worm.

A worm has the capability to spread through a complete network and take advantage of the operating systems. Worms are also able to self-replicate to repeatedly reproduce their data so that they can infect more devices without the need to be activated by the user.

Another type of malware is called ransomware which encrypts files and demands payment from the user, typically in bitcoin or another type of cryptocurrency if they want to regain access.

Although there are viruses that remain dormant for a long time, there are signs that can easily tell you whether a computer is infected with a virus. If you are worried about your machine being susceptible to a virus, here is a list of some symptoms that a virus is present.

• Pop-up windows – pop-ups often encourage the user to visit a specific website or download a file such as an antivirus or another software program.

• Frequent crashes – If your device or computer keeps crashing or shutting down for no reason, a virus might have infected your machine.

• Slower computer performance – If you notice that the processing speed has been unusually slow when you’re doing basic tasks, it could also be a sign of a virus.

• Different browser homepage – A virus can modify your normal homepage to a different website with no option for you to change it.

• Mass emailing your email contacts – Viruses also use email to spread themselves by sending out infected content to your contact list. You may not immediately notice this behavior unless one of your contacts notifies you of the suspicious email they received.

• Unknown programs upon startup – You can check your list of active programs to see if there are any names that are unfamiliar to you. If you see one, it might be caused by a virus.

• Password change – Strange activities that you did not initiate such as changing passwords can prevent you from accessing your account or your computer.

The best method to prevent your computer from being infected is to install an anti-virus or protection software from a trusted brand such as Avira or Total AV. If you’re unsure which anti-virus software to use, you can take advantage of the free trials offered by anti-virus companies. You can try out the benefits and determine which ones are good for an upgrade. There are other methods to protect devices and computers from viruses.

• You should also know by now to steer clear of pop-up ads despite the temptation to click on one.

• Scan files attached to an email before you download and save them to your computer.

• Check the sender before opening any email attachments. If the sender is unknown, delete the email immediately and report it to your email provider.

• Double-check files obtained through a file-sharing program.

• Similar to email, check the contents and links included in messages you receive in your social media accounts. This is true even if you know the sender but especially for accounts that you are unfamiliar with.