Nobody wants to catch a virus – least of all your computer.
It stores all your important documents, photos and messages. Plus it’s your gateway to the rest of the world; without it, your ability to communicate is severely limited.
But viruses and other malware put all of that in jeopardy.
Just as a real-world virus will leave you stuck in bed and supremely uncomfortable, a computer virus will damage your computer’s health.
A virus could prevent you from going online, spam you with ads and errors or corrupt your system files. It could steal your passwords or even lock your entire hard drive unless you pay a ransom.
You can get viruses from websites, downloads, ads, torrents, emails and even USB keys. And without antivirus software, you might not even know it until it’s too late.
Antivirus software monitors your computer for threats, blocks malicious files and alerts you when it detects something amiss.
It’s like a flu shot, face mask and on-call doctor rolled into one tidy package.
Whether you’re running Windows, macOS, Linux, Android or iOS, an antivirus program is a necessity. And thankfully, it couldn’t be easier to set up.
What Is a Virus?
In real life, a virus is a tiny organism that resides in other, larger organisms like people and animals. Its contagious nature means that it can spread from host to host, causing all kinds of ill effects along the way.
A computer virus, also known as malware, behaves very similarly.
Initially, malware is created by a malicious programmer intending to annoy, monitor or steal from unsuspecting users. But after its creation, malware spreads to different computers in the form of a file or files.
All the malware’s creator has to do is kick back and wait for the data to flow in. The malware does the rest — spreading, damaging and corrupting as it goes.
Just as the flu virus causes fever, chills, aches and cough when it infects a new host, a computer virus can wreak havoc on each device it infects.
Exactly what damage depends on the type of malware. And boy, there are plenty of them!
Viruses vs. Worms vs. Trojans
The term “virus” is frequently used to refer to all types of unwanted or dangerous software, aka malware.
But malware can actually be split into three distinct categories: viruses, worms and Trojans.
Some malware begins working as soon as it reaches a new victim, with no user input required. It’s a standalone piece of malware that doesn’t need any extra assistance to run.
This type of malware is known as a worm. Worms usually spread via networks, though a few can spread through USB keys and other portable storage devices.
Other malware can’t exist without a host. It’s dependent on another file, malicious or otherwise, to run — in other words, it’s a parasite.
This type of malware is known as a virus.
Worms and viruses are both self-replicating. They copy themselves onto other computers through your network (worms) or into other files (viruses) in order to spread.
Trojans, on the other hand, don’t self-replicate. They rely wholly on users to spread them, usually by downloading files.
The name “Trojan” comes from the infamous Trojan horse used by the ancient Greeks to conquer the independent city of Troy.
A large wooden horse that appeared to be a generous gift actually contained dozens of enemy warriors. After getting past the fortified walls of Troy by hiding in the horse, the Greeks emerged and began their slaughter.
Computer Trojans prove that all these years later, that tactic still works.
First, you download a file or visit a website that seems innocuous and trustworthy. But when you open that file or website, you’re also activating the Trojan’s hidden malicious code.
Sometimes the website or file even turns out to be legit — just with some nasty code tacked onto it.
The distinction between worm, virus and Trojan doesn’t really matter for most purposes. If you’re infected, you’re infected — doesn’t matter how.
But it’s good to be aware of the difference in terminology, as the removal process can sometimes differ between the three types.
Like a real-world secret agent, spyware doesn’t burst onto the scene with guns ablaze. It prefers a sneakier approach to its attack: remain undetected and take information, not lives.
Rather than damaging your files or disrupting your activity, spyware runs in the background as silently as possible. It needs to keep a low profile and remain on your machine as long as possible.
That’s because spyware’s job is to steal your data.
Sometimes this involves sending your personal files back to its creator. More frequently, though, spyware actively monitors what you do and sends that data back instead.
Keylogging is a particularly lucrative spyware function. Your keystrokes and/or mouse movements are logged and sensitive information is extracted from those logs.
So when you type in “gmail.com” and enter your email address and password, the spyware records those keystrokes.
The creator then knows your login credentials for your Gmail account. From there, even more data can be stolen and more of your accounts can be compromised.
Nobody likes ads, which is why over 25% of internet users use an ad blocker.
But ad blockers mean that whoever’s displaying the ads loses out on potential revenue. Some of these would-be profiteers have decided to try a more forceful approach: adware.
These programs may or may not function as intended, but they have one thing in common. They all bombard you with ads — pop-ups, banner ads, notification ads, toolbars, you name it.
Not all adware is necessarily malicious. Sometimes it’s truly a legitimate program that’s been laden with ads in an attempt to make the creator some money.
But often, adware serves no purpose other than displaying ads. In these cases, it’s very clearly classified as malware — it benefits nobody but its creator in any way.
Sometimes, the goal of malware is to get as deep into your system as possible. These malware programs are known as backdoors.
Backdoors burrow into your system files and gain unauthorized access to critical code and commands, hence their name. From there, they can do pretty much whatever they want.
Some backdoors steal files and log keystrokes like spyware. They may target a specific application to snoop in databases and bogart sensitive information.
Others use their newfound control to download other malware and activate it. If a certain malware program needs higher-level system access to work, the backdoor can provide, well, a backdoor to those necessary files.
And other backdoors, for no discernible reason other than the sake of destruction, corrupt your system and hardware. They could break your OS or physically damage your device by overheating internal components.
You download an antivirus program, run it, and oh, look at that, you’ve got 24 viruses! For your safety, your computer has been completely locked down until you pay $500 to remove the viruses.
You’re doing some completely innocent web browsing when suddenly, your screen is taken over by the FBI seal. Supposedly, you’ve been caught violating several cybercrime laws and must pay a $1,000 fine to use the internet again.
The boss needs you to edit a file for him, but when you try to open it, you get a weird error message. Typo-ridden and adorned with ASCII art, it tells you that the file has been encrypted and can only be recovered if you send 0.47 Bitcoins to an anonymous hacker.
In all of these situations, you’re a victim of ransomware.
This type of malware holds your files, data or entire computer hostage until you drain your bank account for its creator.
Some ransomware attempts to appear official, using logos from the CIA or Microsoft to persuade you to pony up.
Others don’t even try to hide their malice, letting you know upfront that you’re being hacked and extorted.
Worst of all, there’s no guarantee you’ll get your computer back even if you pay.
Some ransomware makes good on its promise to return your data, but others simply take the money and run. This leaves your data inaccessible forever — and your wallet empty.
This is a relatively new type of malware that’s risen in popularity as cryptocurrencies like Bitcoin have gained prominence.
Cryptocurrency can be purchased with traditional money. But it can also be mined.
Mining utilizes your computer to perform complex math calculations that generate new coins and keep track of the world’s cryptocurrency transactions. In return, you get a bit of coin for yourself.
But mining is an extremely demanding task, requiring huge amounts of processing power to see any substantial return. Dedicated mining machines need thousands of dollars of CPUs and GPUs to make it worth the while.
Rather than making such a big investment, some would-be miners use malware to achieve the same end. They create crypto-mining malware that hijacks its victims’ computers to mine cryptocurrency and generate money.
When you’re infected with crypto mining malware, your computer’s performance will drop until it’s barely usable.
All of your resources — processing power, memory, electricity — are being eaten up by the miner, leaving none for your own uses.
And you’re just one of the thousands of infected users who have fallen victim to the greedy hacker. Without purchasing any equipment or using any of their own resources, they’ve created an automated way to rack up the Bitcoins for themselves.
How Does Antivirus Software Work?
So malware sucks — we’ve established that pretty well. At best, it’s annoying; at worst, it can drain your savings and ruin your life.
But us innocent computer users aren’t totally helpless against these threats. We’ve got our own secret weapon: antivirus software.
Antivirus or anti-malware software protects your computer from all varieties of malware. It runs in the background and scans your computer for suspicious files, code and internet traffic.
If you try to download a file or run a program that contains malicious code, your antivirus program will alert you and tell you your options.
And if you suspect that you’re infected with malware anyway, you can have your antivirus program scan every file on your computer. It’ll take some time, but the analysis will reveal any malware that’s lurking on your system.
If you are infected, your antivirus program can remove the malicious files and repair any damage that was caused. It will also recommend any additional steps you should take to protect yourself.
As new malware is discovered, antivirus developers update their databases to detect it. This ensures that users are always protected against the latest threats.
What Is the Best Antivirus Software for Each OS?
All OSes are vulnerable to malware, regardless of what the rumors say.
Windows or Mac, Android or iOS, desktop or mobile device, it doesn’t matter. There’s malware out there for your OS, and without antivirus software, it’s not a matter of if you get infected, but when.
That’s why we’ve put together our list of the best antivirus software for every OS. With both free and paid options, there’s no excuse for not being protected.
Read on and find out the best way to defeat malware on every device!
The Best Antivirus Software for Windows
Ah, Windows! It’s the most popular consumer desktop OS… and the most infamous malware target.
Over its lifespan, Windows has been the target of over 900 million different malware programs. That’s nearly three times the population of the USA, or three-quarters the population of China!
Every month, Windows is targeted by four to seven million new malware programs (PDF link).
That’s why all Windows users need to be running antivirus software at all times. Here are our recommendations.
Trend Micro Antivirus+ Security ($29.95/year)
With perfect scores in Protection and Usability from security institute AV-Test, Trend Micro Antivirus+ Security is our top pick for Windows antivirus software.
It protects you against all the usual suspects — phishing emails, compromised websites, sneaky Trojans, and foul worms will all be kept at bay. Plus it’s equipped to defend against the latest ransomware.
The program itself isn’t bulky and difficult to understand like some other antivirus programs. It’s clean and presents everything in an easy-to-read format that’s informative to all levels of computer users.
And at $29.95 a year for one computer, Trend Micro Antivirus+ Security is among the more affordable premium antivirus options out there.
Excellent security that doesn’t break the bank — now that’s something we can get behind!
Windows Defender (Free)
Believe it or not, Microsoft’s built-in antivirus software is actually pretty decent!
Windows Defender was much-maligned when it first appeared in Windows Vista. But now, in Windows 10, it performs as well or better than many third-party solutions.
In testing, Windows Defender achieved a perfect score in Protection, identifying nearly 100% of all malware programs it was faced with. It scored a 5.5/6 in both the Performance and False Positives categories.
Windows Defender Antivirus missed only two out of thousands of malware programs in the test. Both of those malware programs were blocked by the Application Control part of the larger Windows Defender security suite.
Those are great results, demonstrating some of the best antivirus protection in the biz.
Windows Defender comes preinstalled on all Windows 10 devices, and you can’t uninstall it — so you might as well use it! It’s lightweight and well-integrated with the rest of the Windows OS.
To open and configure Windows Defender, go to Settings > Update and Security > Windows Security > Open Windows Security.
Other Windows Antivirus Options
You’ve got plenty of other options for Windows antivirus software.
Bitdefender Antivirus Plus 2020 will cost you $24.99 a year for protection on three PCs. In addition to stopping malware, it can help you pick the best system settings and even includes a VPN.
Avast Free Antivirus includes a password manager and WiFi security in addition to antivirus protection. The $69.99/year premium version includes secure file deletion, an advanced firewall and state-of-the-art ransomware protection.
Kaspersky Anti-Virus costs $29.99 a year to protect three PCs from the latest malware, including crypto miners and ransomware. There’s also the cloud-based Kaspersky Security Cloud, which provides antivirus protection for free.
ClamWin is a free, open-source antivirus program that integrates with Microsoft Outlook for email scanning. You’ll need to manually scan files as there’s no real-time protection, but it’s fantastic in combination with Windows Defender.
The Best Antivirus for macOS
For a long time, Mac users insisted that they were invulnerable to malware. But that statement wasn’t true then, and it certainly isn’t now!
Windows may be the more popular target, but macOS is fare from immune. In 2018, over 94,000 macOS malware attacks were discovered.
If you’re running macOS, don’t let your relative safety make you complacent. Running an antivirus program is still highly recommended.
Intego Mac Internet Security X9 ($39.99/year)
Intego specializes in Macs, which is why their Mac Internet Security X9 is so highly regarded in the security industry.
Real-time scanning detects both Mac-specific threats and ones directed at PCs. Why? Because though PC malware can’t infect your computer, you can still spread it to Windows computers.
A nasty worm could be lying in wait on your Mac, unable to do anything except wait for your friend’s Windows computer to join your network.
Then it’s a matter of seconds before it spreads to its new victim, who will bear the full brunt of its destruction.
Intego Mac Internet Security X9 scans downloads, websites, emails, networks, zip files and even iOS devices that connect to your Mac. It’s lightweight and attractive, so it blends right in with the rest of your apps.
Also included is the NetBarrier X9 automatic firewall, which adjusts to your network usage for perfect protection. It prevents unexpected connections that can transmit malware or allow hackers into your computer.
At $39.99 a year for one Mac, Intego Mac Internet Security X9 is well worth the cost. It’s created by Mac specialists for Mac enthusiasts, so you know you’re getting the best protection.
Avast Security for Mac (Free or $59.99.year)
Avast’s Windows antivirus is extremely popular, but its Security for Mac software is just as powerful.
It got perfect scores on AV-Test’s Protection and Usability tests. And it’s surprisingly full-featured for a free antivirus program!
Avast Security for Mac blocks web trackers, malicious sites, phishing emails and all kinds of malware. Ransomware, spyware, adware and Trojans will all be stopped in their tracks.
There’s also an on-demand WiFi scan that checks your router and any connected devices for threats. If you’re on a public network, running this will tell you if any bad actors are around.
For $59.99 a year, you can upgrade to Avast Premium Security. You’ll get real-time WiFi scanning and extra ransomware protection for your most precious files.
Other Mac Antivirus Options
You’ve got plenty of excellent options for antivirus software on macOS. Here are a few more of our top picks.
ClamXAV provides protection for three Macs for $29.95 a year. It’s exclusively for macOS but protects against Windows malware as well, so you don’t unwittingly spread PC viruses.
F-Secure SAFE won AV-Test’s 2018 Best Protection Award, in part thanks to its built-in parental controls. $34.99 a year gets you advanced ransomware and banking protection.
Norton 360 Standard costs $29.99 a year and includes many extras. A VPN, password manager, dark web monitoring and 10GB cloud storage round out this premium antivirus package.
The Best Antivirus for Linux
Most people don’t think of Linux as a malware target, but the incidence of Linux malware rose 300% from 2015 to 2016 (PDF link).
And if you run Windows programs on your Linux computer using Wine, Windows viruses could still infect your computer.
We recommend using an antivirus program on Linux even if you don’t think you’re at risk. Better safe than sorry!
Comodo Antivirus for Linux (Free)
Available for Ubuntu, Mint, Debian, Redhat, Fedora, CentOS, SUSE and OpenSUSE, Comodo Antivirus for Linux is a fantastic option.
It can handle real-time scanning, scheduled scans and on-demand scans. Threat definitions are updated from the cloud automatically, so you’re always safe from the latest malware.
Comodo Antivirus for Linux can also integrate with your mail client. Your emails and attachments will be automatically scanned, ensuring that you never unwittingly open an infected message.
Like most Linux antivirus programs, Comodo Antivirus for Linux isn’t as full-featured as its Windows and macOS counterparts. But it still performs admirably at its main task: keeping malware off your computer.
All Linux distros can run ClamAV, a free and open-source antivirus program.
ClamAV can be run from the Terminal via commands or in a GUI, whichever you prefer. It has two modes: manual and automated (daemon) mode.
In manual mode, ClamAV will only scan the files you instruct it to. For real-time scanning of emails and other files, use daemon mode.
Should ClamAV find any infected files, it takes just one command to delete them. It also has a scheduling function that allows you to perform regular scans automatically.
It’s not fancy, but it does everything it needs to, and it does so in a very compact, resource-friendly package. And it stays true to the origins of Linux: free, secure and open-source.
Other Linux Antivirus Software
Your Linux antivirus options are more limited than with other OSes, but you’ve still got a good selection. Here are some other great programs to try.
Sophos Antivirus for Linux is a free antivirus program that handles both real-time and on-demand scanning. It scans for Linux malware as well as Windows, Mac and Android malware.
ESET NOD32 Antivirus 4 for Linux costs $39.99 a year for one computer, bilking the trend of free Linux software. But it’s ideal for those used to a more traditional antivirus UI and name-brand security.
The Best Antivirus Software for Android
Mobile malware is growing fast, and Android malware makes up the lion’s share of it. In 2018, around 600,000 malware programs per month (PDF link) were distributed to Android devices.
Running an antivirus app on your Android device is a must — unless you want it hijacked for Bitcoin mining or flooded with ads. Here are our top choices.
AVG Antivirus for Android (Free or $14.99/year)
From one of the most trusted names in antivirus software comes AVG Antivirus for Android. It’s a free app that protects you from all kinds of mobile mayhem.
Trojans, ransomware, crypto miners and other malware will all be kept at bay. But so will unwanted callers, unsafe settings and even thieves, the latter thanks to AVG’s anti-theft feature.
The base app is always free, but $14.99 a year will upgrade you to Pro status. This gets you several handy features.
App Lock lets you protect individual apps and files with a PIN or fingerprint, and Device Lock locks your phone if the SIM card is changed. Camera Trap takes a discreet photo of anyone who fails to unlock your phone three times.
Kaspersky Internet Security for Android ($11.99/year)
For automatic malware scanning, SMS phishing protection and advanced anti-theft tools, try Kaspersky Internet Security for Android.
A nominal yearly fee gets you some of the industry’s best malware protection. You also get tools to protect and reclaim your data if your phone is lost or stolen.
If desired, you can protect your individual apps, calls, and texts with an extra passcode. Kaspersky Internet Security for Android even integrates with Android Wear, so your smartwatch can be protected as well.
Other Android Antivirus Options
Many Android apps claim to protect your phone from malware, but alas, many of them are malicious themselves. We recommend sticking with reputable developers, like these, to ensure your security.
Sophos Intercept X for Mobile is an ad-free Android antivirus app with a 100% Protection rating from AV-Test. It scans sites, downloads, links, apps and WiFi, and can generate two-factor authentication keys.
Trend Micro Mobile Security for Android stops malware in its tracks thanks to its cloud-based security database. This free app blocks malicious websites and prevents apps from loading them, too.
V3 Mobile Security is an AV-TEST-certified mobile malware solution that’s great for older devices. It’s not as resource-hungry as other antivirus apps but still provides excellent protection.
The Best Antivirus for iOS
Like macOS, iOS has a reputation for being immune to malware. And it’s mostly true: other than jailbroken devices, iPhones and iPads rarely get infected.
But every so often, a new iOS malware program pops up — and when that happens, you’ll be glad you had an antivirus app.
Avira Mobile Security (Free)
There isn’t a lot of iOS malware out there, so Avira Mobile Security sports a lot of other security features.
In addition to antivirus, Avira provides anti-theft and phone-locating features. It also scans the internet regularly and alerts you if it finds that your email has been involved in a data breach.
Avira Mobile Security lets you know when apps or websites are attempting to steal your files or other data. And you can use the Activity Report to find out if you’ve visited any shifty sites recently.
The app also includes a Device Analyzer, which helps you free up your phone’s memory and storage.
And for just over $1.50/year, you can upgrade to Premium and access the Avira Phantom Pro VPN. You also get priority tech support to help you with all your mobile security needs.
Lookout Personal for iOS (Free, $29.99/year or $99.99/year)
With “predictive security” technology that stops threats before they reach you, Lookout Personal for iOS is a must-have app.
The free version lets you know when your apps or system are out of date and provides theft alerts. We recommend the $29.99/year Premium plan for maximum protection.
Lookout Premium doesn’t just protect against malware. It lets you know when you’re on a compromised WiFi network and alerts you if sites try to steal your information.
The app actively monitors the web and lets you know if your identity has been compromised. If your email or other personal information gets leaked, you’ll know right away.
$99.99 a year gets you Lookout Premium Plus, which comes with social media and SSN monitoring. It also includes $1 million in identity theft insurance and recovery assistance.
Other iOS Antivirus Software
You don’t have a ton of options for antivirus apps on iOS. That’s probably because there just aren’t as many malware programs that target iOS users.
But if you’re still on the hunt, take a look at these apps.
Trend Micro Mobile Security for iOS scans for malware, unsafe WiFi and invasive trackers. It also blocks ads and helps prevent excess data consumption — all for free.
Malwarebytes Mobile Security gives you ad blocking and SMS phishing protection for free. $11.99 a year gets you malware protection, malicious site blocking and fraudulent call alerts.
Malware isn’t going away anytime soon. The best we can do is protect ourselves against it.
And the only way to reliably do so is by using antivirus software.
With plentiful options both free and paid, there’s an antivirus program out there that’s perfect for you.
Try a few and see which one clicks. When the next big threat comes around, you’ll be glad you did!
Summary: Antivirus, or anti-malware, software protects you from attacks that can put your files, data, and device at risk. With millions of malware programs out in the wild, an antivirus app is the best way to stay safe.