What is antivirus software? Explained for beginners

In today's increasingly digital world, safeguarding our information and devices is paramount, and this begins with robust security software. An antivirus program serves as a protective shield for your computer, phone, tablet, and other devices, shielding them from potential attacks by malicious software. It not only identifies and blocks viruses, a particular type of malicious program, but also guards against a wide array of other digital hazards.

PCWorld consistently provides up-to-date coverage on viruses and other cyber threats, along with strategies for defense. To explore the top antivirus software options in 2024, don't miss our comprehensive guide highlighting the best antivirus programs available.

Understanding computer viruses

To grasp the function of antivirus software, it's essential to understand the concept of a computer virus. In simple terms, a virus is a program that installs itself on your computer and then spreads to other computers through networks or the internet, much like a biological virus spreads through cells.

The actions of a virus vary depending on its specific design, but they are generally harmful. Early computer viruses were often created for mischief, causing damage to computer systems. For instance, the notorious "ILOVEYOU" virus spread through email downloads, overwriting files on hard drives with useless data, rendering the computer unstable and requiring a complete wipe.

Some viruses are crafted to take remote control of your computer, creating a hidden network known as a "botnet." These botnets, like MyDoom, can be utilized to disseminate spam or scams, or to launch distributed denial-of-service (DDoS) attacks aimed at shutting down web services.

However, the most dangerous type of virus today aims to steal personal information from users. Spyware or spybot programs search your computer files for sensitive data like login credentials or bank account details. Ransomware, on the other hand, encrypts your files and demands payment to regain access. These malicious programs are often distributed through deceptive emails or websites posing as legitimate entities, a tactic known as "phishing."

In some cases, the software may not exhibit the self-replicating behavior typical of viruses. Terms like "worm," "trojan," or the broader term "malware" may be more fitting to describe such malicious software.

What is the function of antivirus software?

When antivirus software detects malware in a file, it immediately isolates the file to prevent it from affecting other files or programs. Once isolated, the software deletes the malicious files thoroughly and typically notifies the user of the action taken. While this protection method is highly effective, it's not flawless. Malware must be identified before it can be added to the detection database, meaning it may need to be active on the internet before detection. This highlights the importance of practicing basic computer security, such as avoiding downloads from unknown sources or opening email attachments from untrusted senders.

What is the purpose of antivirus software?

Antivirus software is created to identify and prevent a broad range of threats, which may be referred to as "antivirus," "protection suite," or "defender." These programs utilize various techniques to detect, contain, and eliminate viruses and malware, while also conducting regular scans of your computer and network traffic for potential threats. Norton 360 Deluxe is currently recommended as our top choice for comprehensive security software.

Do all computers require antivirus software?

If you own a Windows desktop or laptop that's online, having antivirus software is essential. With personal computers connecting to the internet for decades, viruses and malware have been circulating just as long. Browsing the internet without any protection is akin to swimming in contaminated waters - sooner or later, you'll encounter an infection. Thankfully, Windows PCs come with built-in security known as Windows Security, offering basic antivirus and firewall features at no extra cost. Keeping this software updated, which it typically does automatically through Windows Update, provides a fundamental level of protection. However, what about other internet-connected devices like smartphones, tablets, smart TVs, security cameras, or smart lights? While smartphones are prone to viruses and malware due to the wealth of personal data they contain, they're generally safer than desktops and laptops. Both iOS and Android phones restrict downloads to official app stores like the Apple App Store and Google Play Store, reducing the risk of encountering malicious software.

Apple and Google oversee the security measures for these applications from the server side. While not flawless, their detection filters have generally been effective in preventing viruses, spyware, and malware from infiltrating their platforms. As a result, most users find the built-in protection provided by these platforms sufficient, negating the need for additional antivirus software.

However, there's a slight distinction with Android phones. Unlike iPhones, many Android devices allow users to install programs that haven't undergone Google's pre-approval process, a practice known as side-loading. Similar to installing third-party software on Windows, caution is advised when obtaining software through this method. Nonetheless, Google has implemented Play Protect, a system that conducts basic antivirus and anti-malware scans on all applications, including those installed via side-loading. For users seeking enhanced protection, additional options are available.

This concept extends to any device that acquires its content and applications from managed sources rather than having unrestricted access to the internet, such as smart TVs, e-readers, and smartwatches. As long as the content management entity remains vigilant, the risk of device-specific viruses is minimal, especially since these devices typically contain limited personal information. While exceptions exist, as almost any connected device can potentially be compromised, malevolent actors tend to prioritize other targets over these gadgets.

Difference between antivirus and a firewall

Antivirus software mainly examines the files and applications stored on your computer, while a firewall scrutinizes the traffic entering and leaving your computer, both locally and over the internet. Firewalls play a crucial role in security by blocking potentially harmful data from entering or leaving your system, which helps prevent unauthorized transmission of personal information or remote control of your computer by external programs.

Some antivirus programs incorporate basic firewall features in addition to their file and program scanning capabilities. For instance, Windows Defender, a common antivirus utility, includes Defender Firewall as part of the integrated Windows Security suite. Built-in firewalls are typically sufficient for everyday security needs, but specialized firewall software (or more advanced hardware-based solutions) are typically deployed by large enterprises or organizations, often requiring specialized management by cybersecurity experts.

Is McAfee Antivirus an effective antivirus solution?

McAfee, a veteran in the field of PC security, is well aware of its reputation. Its software comes with a premium price tag, making it one of the priciest options per device. Despite offering unique features like the "file shredder" for secure deletion and a home network analyzer, it may not be the best choice for budget-conscious users. Additionally, the interface for these features could use some improvement.

Is Windows Defender an effective antivirus solution?

The default security settings provided with Windows weren't always sufficient in the past. Two decades ago, it was considered risky to use Windows without additional security software. However, Microsoft has put significant effort into enhancing the security of Windows without requiring additional software, whether paid or free. So, in simple terms, yes, Windows Defender is quite effective. The antivirus tool integrated into Windows receives regular updates for detecting the latest threats, and these updates are seamlessly integrated into the Windows operating system. Most of the time, it operates silently in the background, unless it identifies and resolves a threat directly. The same applies to the basic firewall included in Windows Security: Apart from occasional adjustments needed to grant network access to certain third-party apps and games, you may forget it's even active.

If you're using Windows and don't have the budget for more advanced security solutions, you can rest assured. You'll still be adequately protected as long as you keep your computer updated via Windows Update and refrain from downloading particularly dubious software.

Is Norton 360 an effective antivirus solution?

Is Norton a suitable option for safeguarding your PC, especially if it contains important or sensitive data, or if it's shared with users who may not exercise the best judgment? Along with typical file scanning capabilities, the subscription offers additional features such as VPN access, dark web monitoring for account breach alerts, complimentary cloud storage, and a password monitor. Although it comes at a higher cost, Norton serves as a comprehensive security solution for up to five devices.

Is AVG Internet Security a worthwhile investment?

Previously, AVG was a popular choice for antivirus software, especially because of its free basic version. However, the free option is no longer available. Nevertheless, AVG remains popular due to its enhanced interface and regular virus scanner updates. It offers a simple and easy-to-use interface, along with additional online security features, while still delivering the effective antivirus protection it's recognized for— all at a more affordable price compared to its competitors.

Is Trend Micro an effective antivirus solution?

In essence, Trend Micro Maximum Security isn't ideal for users with advanced PC maintenance skills. While it's functional and user-friendly, it may not be the best option for those seeking more advanced features. Its advanced functionalities are comparatively weaker and less dependable than competitors, and it doesn't provide significant cost benefits.