You would be surprised at just how many people still think that is a legitimate question. To not beat around the bush, the answer is yes, yesterday, today, and tomorrow. You always need to have an antivirus (plus an anti-malware if possible) running on the system at all times.
Why do some folks think they don’t need an antivirus?
Well, there is this misleading misconception that an antivirus is only needed by people who are not careful online. So you find this called pro-computer-user who says they don’t just visit any website, open any email (or email attachments), and they don’t insert just any thumb drive to their computer.
In short, they think they are practicing safe computing, but little do they know, they desperately need an antivirus in their system. Operating with one for just one hour could have so many Trojans stealthily installed on your system; to say the least.
So why do you need an antivirus?
Well, an antivirus is always your first line of defense against cyber-attacks. Sometimes you might be so careful, but the internet is just like the road; you are only as safe as you are a competent driver in complement to the competency of other drivers.
You might have done all the right things; haven’t visited suspicious websites, didn’t open suspicious attachments, and kept away from inserting just any thumb drive into your USB ports. Well, that ‘safe’ site you keep visiting might have been compromised because they did not update certain plugins that trusted email contact might have had their account hacked, and an email sent to you by hackers without your authorization.
The bottom line is you can’t rely on just your safe practice online to keep yourself safe. Having an antivirus is the prudent thing to do and here is why:
There might be a zero-day vulnerability in the websites you visit or one of the applications running on your computer. The most notorious one for this kind of problems is Adobe Flash. Even if you are a cyber security expert, having no antivirus leaves you completely defenseless as you cannot protect yourself from what you don’t know. However, an antivirus might be able to save you from zero-day vulnerability by running the suspicious application in a sandbox.
Some people have legitimate concerns about running an antivirus in their system, with claims like they slow down your computer. Indeed, older versions of antivirus software like MacAfee and Norton were infamous for this habit. These antiviruses kept your computer running slower than some of the virus software they were meant to protect you from. Then again, even some of the modern antiviruses keep bothering you with notifications and inducements to have you purchase a premium subscription and maintain paying for the premium package. Some are so aggressive on advertising themselves they could easily pass for adware.
On the other hand, computers have gotten faster and more resources rich that a mere antivirus no longer weighs them down. In addition, there is a good number of antivirus out there that don’t keep bothering you with advertisements for the premium package, and some are even built-in the operating systems like the Windows Defender on Windows 10. The best part about Windows Defender is that it doesn’t have junkware, it is light, no ads, and doesn’t keep pestering you about purchasing the premium package.
Users on Windows 7 can download Windows Defender as Microsoft Security Essentials.
So you got an antivirus! Here’s why you still need to be careful
Just because you now have an antivirus install in your system, that doesn’t mean you should drop your entire online best practice defense. You should still follow due diligence online by not downloading and running any software you pick off the internet, keep all your software updated, uninstall software that are most of the time vulnerable such as Java.