Computer viruses spread easily and can cause a lot of damage. This is why anti-virus programmes make a decisive contribution to IT security. But what exactly is a computer virus and how does a virus scanner work?


Computer viruses spread easily and can cause a lot of damage. Therefore, antivirus programs make a decisive contribution to IT security. But what actually is a computer virus and how does a virus scanner work?

What is a computer virus?

Computer viruses are a form of malicious software, so-called malware, which can infect a computer. Computer viruses get into an operating system without the user noticing. There, they slowly spread within the system by attaching themselves to various programs. The goal is to damage, delete or manipulate data or files. Often, data loss occurs. The peculiarity of computer viruses, unlike worms, is that they can replicate themselves, which allows them to spread throughout the system and all attached drives.

Computer viruses enter a computer through various ways. Common ones are:

E-mail icon


Downloads icon


Messaging services icon

Messaging services

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Outdated software

How does a computer virus work?

Unlike computer worms, viruses cannot execute themselves. For a virus to become active on a computer, it therefore requires a trigger. This can be a click by the user on a certain button or the opening of a program. It is also possible that the virus is activated after the expiration of a period of time defined by the programmer. When the computer virus is active, it spreads through various files while constantly replicating itself and causing the damage planned by the programmer.

In order to disguise the origin of the virus, the active phase of the virus is often preceded by a dormant phase. During this time, the virus is inactive and is only released after some time. This is to ensure that the virus remains undetected for as long as possible.

Countless virus microscopic enhanced virus particles are floating in the air.

Antivirus: What are virus scanners?

An antivirus software is a program that is designed to protect against computer viruses. Often the software is also called a virus scanner. The goal is that the antivirus software detects and removes viruses as indepen­dently as possible. As a rule, this is achieved before the virus becomes active and causes damage. An antivirus program contributes to the security of IT systems and therefore belongs to the basic equipment for every computer.

For companies in particular, it can make sense to rely on  managed antivirus. Here, the management of the defense software is left to experts - such as the profes­sionals at IT-Kompass. In addition to an antivirus program, employees should also receive  training on IT securityso that they can recognize suspicious e-mail attachments or dubious sites on the Internet and prevent viruses from infecting the computer in the first place.

What does a virus scanner do?

Virus scanners check the computer system for harmful virus software. If a corre­sponding program is found, on the one hand the user is notified about it, on the other hand the antivirus program tries to remove the threat and prevent or stop its spread.

Computer viruses spread in the system by attaching themselves to files. In the process, the viruses manipulate the files to mark them as already infected. This signal, which is actually directed at the other viruses, is also detected by the antivirus software. A virus scanner searches the computer systema­tically for these changes. Since there are always new viruses, antivirus programs must also be constantly kept up to date to ensure the best possible protection.

So you should not do without good antivirus software in your company under any circum­stances, because it makes a significant contribution to your IT security.