It can be easy to take antivirus software for granted. Most users just install their preferred software, set up regular scans, and go about their life. But what’s going on beneath the hood of your antivirus software is both complex and fascinating. The business of antivirus software is a constant game of chess between the criminals who create malicious code and the men and women committed to stopping it, and understanding the basics can help you better protect your computer from intrusion.

Types of Malicious Code

While we may generally refer to any malicious, targeted code as a “virus”, the truth is more complicated. Crafting code that compromises your machine and personal information is big business, and criminals have become increasingly sophisticated in the tools they use. There are generally three types of malicious code you have to worry about, and the best antivirus software is designed to counteract all of them.

• Worms are a rapidly replicating form of malicious code, and their general purpose is to infect as many machines as possible. They gain access to this network through weaknesses in a single computer and then use that access to travel to any connected computers. The threat of worms makes it important for all connected machines to have meaningful antivirus protection.

• Malware takes the form of usually innocuous software, taking advantage of the user’s trust to find purchase in their computer. This is why the best antivirus software scans every new piece of software you download to your machine.

• A virus is simply a piece of code with the ability to copy itself. It then attaches itself to a piece of software that allows it to execute commands, usually for the purpose of destroying or corrupting data.

How Antivirus Software Combats the Problem

The most effective method for running an antivirus scan relies on established databases of existing viruses. When you start a scan of your machine, the software essentially compares the information on your computer to known pieces of malicious code and then flags these signatures as potential dangers. Since the library of viruses grow with each passing day, it’s important to keep your antivirus program up-to-date. This takes the form of specific detection, which looks for the specific characteristics of a virus; but it also takes the form of generic detection, which looks to identify common traits prevalent in the more popular “families” of viruses.

But since new forms of viruses appear regularly, the best antivirus software also accounts for viruses that may not yet be detected. It does this by checking for unusual behaviors in your computer’s activity, in much the same way that a doctor may track health symptoms without yet knowing their root cause. This is known as heuristic detection.

The Future of Antivirus Software

For years, the industry has been caught in something of a cold war between virus designers and those fighting them, but many in the business are looking for a way to break that stalemate. While we can’t predict what future antivirus software may take, there are a few promising leads.

There’s a move in the industry away from “blacklisting” nefarious software and instead towards “whitelisting” benign or beneficial code. The bold new notion of “protective intelligence”, meanwhile, would rely less on securing each individual computer locally and instead perform scans from the cloud. Given the large-scale damage caused by worms, this could be a sensible decision to make.