Antivirus software is often perceived as pesky and annoying. Warnings keep popping up at the most inopportune times, disrupting concentration and workflow. Sometimes an over-zealous antivirus application blocks even necessary, virus-free software.
Time for a quick tour behind the scenes: what does antivirus software do? How does it work? And is it even worth paying for virus protection?
How can virus and malware protection help?
Antivirus developers like to say that without it you would be lost. Or at least your data would be gone. Some Windows users take the opposite view: antivirus programs reduce system performance, annoy you with unnecessary warnings and block perfectly harmless applications, and yet real malware can still slip into your computer.
Although antivirus software can be incredibly annoying, it provides the necessary “insurance”. Without antivirus software, any network interactions could result in malware infecting your computer. In short: Without antivirus protection, using the Internet would become impossible.
The principle that currently available anti-virus programs use to protect users against malware (for short: “malware”) is essentially the same. Antivirus protection modules check all files in real time, that is, as soon as they reach the computer. A web protection module tries to prevent access to malicious sites. Finally, the anti-virus scanner checks all local data for possible infections at the user’s request.
All of these functions do require processing power; in other words, they reduce system performance to a certain extent. However, there are techniques that are used to reduce this effect. One of them is the layered approach to detecting malware.
A brief introduction to the workings of antivirus protection
The easiest way to detect threats is to compare code against “signatures” of known malware. Simply put, it boils down to checking whether the file being analyzed matches a checksum from a blacklist.
The disadvantage of this approach is that attackers can bypass signature recognition by making minor changes to the code. Heuristic analysis is a method in which the antivirus program uses advanced detection criteria by matching a broader pattern, such as a specific piece of code instead of the entire file.
The advantage of heuristic analysis is that it easily recognizes different threat variants. But. In the case of antivirus software, there is always a “but” … Because heuristics involve some degree of assumption, they tend to mistake ordinary harmless applications for malware.
Another approach is behavioral analysis. For this purpose, suspicious applications are first run in a sandbox isolated from the operating system. However, this detection method is very resource intensive, i.e. when the sandbox is run on your computer, it can significantly affect its performance.
To get around these problems, antivirus software developers have developed online file reputation checking systems. If a local antivirus program is unsure about the purity of a file, it can immediately contact its creator’s servers to see if it is on a centralized whitelist. If it is confirmed that the code is safe, the file will be allowed to run. If the code is unknown, it is sent as a sample to the developer’s servers for centralized analysis. There, the sample is run in a virtual Windows environment, where its behavior is checked for unusual activity.
All this usually takes place without any user involvement. That’s why antivirus programs can be thought of as kind little elves who work unnoticed and protect you. However, even elves are not immune to mistakes.