What Is Antivirus Software? How It Can Protect Your Device

Viruses are a danger to anyone who uses the Internet. They can severely damage software and devices. Antivirus software programs are the best defense against a computer virus and many other kinds of malware. If you’re looking to protect your device and your data, read on to understand how antivirus programs work and how you can choose the one that’s best for you.

What is a computer virus?

A computer virus is a type of malware that spreads from system to system, replicating itself and damaging each host that it overtakes. While the term “virus” is rather broad – it can refer to worms, spyware, Trojan horses, keyloggers, scareware, or many other kinds of malware – all viruses spread by attaching to other programs and files within your system. They may be merely annoying or they may cause serious damage. It all depends on what virus it is and the kind of antivirus protection that you have.

There are several ways for a system to become infected with a virus. But often, they are sent via email attachments or other downloadable files.

They could be completely legitimate files infected with malware or links that have been altered to include a virus. Either way, once a virus is downloaded, it alters the way your computer functions. Because these viruses are so easy to download, even without knowing it, an antivirus program is essential.

Antivirus software on a computer

What is antivirus software used for?

Because of the nature of viruses, antivirus programs have many uses. Their primary goal is to detect and remove viruses, as well as other types of malicious software, from your device. They perform scans to find any dangerous or malicious software on your computer and delete it automatically, clearing your device and preventing the viruses from spreading further.

Many antivirus or anti-malware programs also provide other services, such as a firewall. A firewall provides protection against outside cyber attackers by shielding your computer from malicious network traffic. Without a firewall, viruses have a better chance of slipping through your computer’s defenses. Using an antivirus program that also works as a firewall means your personal information and files will be even more protected than they would be if you used the antivirus software or a firewall alone.

How antivirus software works

Once you download it to your computer or device, antivirus software works around the clock. It constantly scans your device and the files on it to check for viruses, malware, or any other harmful software. The software scans using several different methods depending on the program and your computer's needs.

If the software detects a virus, it then quarantines the infected files or programs to keep the virus from spreading further. The software isolates the infected files either in a secure location on the computer or on an attached external storage device. This way, the protection software can take care of the problem without affecting other files or programs on your device.

The software then will attempt to remove the virus. It might be able to simply delete the malicious code from the file; however, in some cases, the entire file must be deleted in order to protect the rest of the computer system.

Even when you don't have an active virus, the antivirus software runs in the background to keep your computer in check. It prevents viruses, blocks dangerous downloads and sites, and often includes other features too. Firewall protection, email scanning, and unsafe site blocking are common features that come with an antivirus program.

Types of antivirus scans

As mentioned above, there are several methods that antivirus software uses to scan for viruses.

Signature-based scanning

Signature-based scanning is the most common method of scanning used by antivirus software. When the software scans a file to check for a virus, it checks the file against a virus signature database. The database contains virus signatures, or the code patterns for specific viruses; this way, the software can see if the file has any known viruses or malicious code.

This type of scanning works well for detecting known viruses, but it doesn't always work against new or unknown viruses since those aren't yet added to the database. Some antivirus programs, therefore, use signature-based scanning in conjunction with another method of scanning to get the most comprehensive results.

Heuristic scanning

Heuristic scanning detects viruses or malware by analyzing the code of a file or program to determine its behavior. It's able to recognize if the file's behavior is abnormal. Since many viruses behave differently than legitimate software, antivirus software can use heuristic scanning methods to identify viruses.

Heuristic scanning relies on code and behavior analysis to determine if a file is acting abnormally. It also sometimes uses a process called sandboxing, which runs the file in an isolated, simulated environment in order to check on the file's behavior without accidentally spreading a virus or malware to other programs.

Reputation-based scanning

Reputation-based scanning determines how trustworthy a file is based on its reputation. The reputation database keeps information about various files, including the file's digital signature, file name, and other metadata. When the antivirus program does a scan, it checks files against the reputation database to determine if it's generally trusted. While this doesn't mean the program will never get a virus, it means it's more likely to be secure and less likely to be flagged as suspicious by the program.

File emulation

Unlike signature-based scanning, which may struggle to detect unknown viruses, file emulation is a method used to detect new malware not yet added to the virus signature database. It runs the file in a controlled environment to prevent the virus from spreading and then monitors the behavior of that virus.

The antivirus software can then execute the file in the controlled environment, which protects the rest of the device and operating system from the virus.

Signs you have a virus and need an antivirus scan

Sometimes viruses lie dormant for long periods of time. It can be difficult to find a virus on your computer without an antivirus software program capable of scanning for infection. However, if you experience any of the following, it may indicate your computer has a virus.

  • Random files and icons that you did not install appear on your desktop.
  • Files disappear from your system.
  • You receive a high number of unusual error messages.
  • On-screen text, graphics, or pop-ups become distorted or unreadable.
  • Hard disks, CD drives or other hardware can’t be accessed.
  • Programs that previously worked properly run slowly or don’t run at all.
  • Your system becomes extremely slow and freezes often.
  • Your system crashes and reboots every few minutes.

Every virus causes a different set of problems; this is by no means an all-encompassing list. Some, for example, expose your IP address, which you can go to the What's My IP Address homepage to see. Others log all your typing activity and siphon your passwords.

Regardless, the symptoms above are several of the most common indicators of a virus. If you experience one or more of them, download a secure antivirus software program as soon as possible and run a scan.

Why is it important to install antivirus software on your computer?

Quite simply, an antivirus program could be the difference between a functional laptop and a completely inoperable one. Viruses corrupt data, software, and programs, sometimes without the user even realizing it. It’s far easier to prevent a problem than to solve one.

Antivirus software prevents viruses from getting onto your device, which prevents them from doing damage to your computer and countless others if the virus were to spread. They provide ransomware protection, spyware protection, and adware protection; essentially, a good program bolsters your defense against any and all kinds of malware.

How to choose a strong antivirus program

Ideally, your antivirus program should be able to protect against not only viruses but also against other malware as well. Spyware and adware should be on your radar, as well as scams that come through via emails, phone calls, or websites. Many antivirus programs also defend against phishing attacks along with malware protection. Choose the program with features that will help guard against the biggest threats in your online life.

Ultimately, however, an antivirus program, like any network security software, should be two things: preventative and efficient. Some antivirus products only fix issues after they’ve happened. Preventing viruses is far easier than dealing with virus removal after the fact.

Choose a program that features a protection plan right off the bat. That way, you don’t have to worry about accidentally harming your computer with downloaded malware or venturing onto dangerous sites in your online activity.

Ensuring your antivirus program is efficient means that it won’t slow down your system or run scans that get in the way of your day-to-day usage. Since the software runs constantly in the background, find a program that performs scans during all of your typical computer tasks, like downloading files and browsing websites. This way, you’ll be protected while you use your device, but you won’t be bogged down by slow speeds.

Which antivirus is best?

There are many antivirus companies and products on the market, so choosing the best antivirus software is difficult. Many have free antivirus software for users on a budget. You can try a free version or free trial from a premium company for a limited time. However, for those looking to stay safe with premium protection, we recommend using one of the following programs: