“Why you don’t need to pay for antivirus software”. Interesting title, but is it true? Yes and no. If you want an amazing free (and cross-platform) antivirus software, use ClamAV. If you suspect a file may have a virus, there are plenty of free online scanners such as virus total that checks the file with over 50 different scanners. The file checker is especially useful for those of you who are torrenting potentially infected files.
Now for the reason I say it both is and isn’t true. The way antivirus works is to create a signature of the virus (what is unique to the particular virus).
So in order to grasp the concept easier:
# This is my personal virus created for this example. The example is in no way close to what actual malware looks like, but is written to be easily comprehensible.
1 Open scripting language
2 Execute code
3 Connect back to attacker’s system
4 Execute more code to compromise system further.
5 Order compromised system to download file “financial information stealer” and execute.
The antivirus distills the above virus and finds that line #5 is unique and will look for it in the future to identify the virus.
Antivirus software also employs what are called heuristics. Heuristics is a methodical approach that attempts to provide a solution when an optimum solution is unrealistic (in other words, an educated guess). How does this apply in the real world? If it looks like malware, acts like malware, it’s probably malware. The main issue with heuristics is that it can provide false positives for software that is doing what it’s supposed to be doing.
Let me dispel the myth that Apple computers can’t get viruses right now. In fact, a virus called the Elk Cloner was written for the Apple II operating system in 1981 by a 15 year old Rich Skrenta. Elk Cloner is believed to be the first large scale virus outbreak in history… and it infected Apple computers. Which means if you’re using a Mac and thought you couldn’t get a virus, you might want to consider doing a scan sooner rather than later.
If you want to scan your system, I recommend the free method using CalmAV (because it’s cross-platform), and at least one other antivirus program (such as Malwarebytes). Run one and then the other. It’s possible to have antivirus programs interfere with each other if you run them at the same time and it’s also possible each antivirus will detect something the other did not.
Lastly, if you are being targeted by someone who knows what they’re doing, no amount of antivirus in the world will save you. Now go scan and protect yourselves that extra byte.