How Does Antivirus Software Work?

We hear a lot about the importance of having antivirus software on our computers, but in today’s evolving world of digital threats to our data and privacy, it’s no longer enough to simply know that we need antivirus software. To be able to make an informed choice about the best AV protection for you, you’ve also got to know something about how antivirus software works.

The term malware, a portmanteau for malicious software, refers to computer viruses as well as many other types of malicious software. Antivirus software was originally developed to detect and remove the viruses. However, with the rapid proliferation of new kinds of malware, today’s antivirus software has had to expand its scope to be able to provide protection against other forms of malware such as ransomware, rootkits, Trojan horses, worms, adware, spyware, phishing, spam, malicious URLs and more.

In order to achieve this level of protection, antivirus solutions now take a multilevel approach to detecting and eliminating cybersecurity threats. The main tactics that they use are described below:

Signature-based detection. This method works in the background, scanning files and downloads and looking for a specific digital code of a virus. If a virus is found in a file, the AV will quarantine or delete the file. Signature-based detection relies on a database of known virus definitions, which is why it’s important that your AV software always be current.

Heuristic-based detection. Unlike signature-based detection that compares digital code to a database of known viruses, heuristic-based detection doesn’t rely on virus signatures. Instead, heuristic detection uses rules and algorithms to look for suspicious commands that might indicate a threat.

Behaviour-based detection. In this form of detection, the focus is on observing the characteristics or behavior of files during execution. Malware is identified by searching for suspicious or abnormal behavior, such as trying to alter host files or modifying keystrokes. Like heuristic-based detection, behavior-based detection does not rely on a set of signature data.

Machine Learning. A form of artificial intelligence, the machine-learning method leverages the computer’s ability to learn and understand malicious and benign programs in order to determine whether a piece of software is a threat.

Data Mining. Data mining is a recent addition to malware detection methods. This method relies on large data sets of malware behavior patterns and uses different data mining and machine learning algorithms so it can analyze the behavior of a file and detect whether or not the file is malicious.

There are many different detection methods used in antivirus software, and because of the ever changing landscape of malware and other cybersecurity threats, new ones are always on the horizon. This is why most antivirus programs today use several different methods of detection. It’s also another reason why it’s important to always make sure your AV program is fully up-to-date.