Types of Computer Viruses

When you hear the word virus what comes to your mind? What is a computer virus?How does it work? What will it do to my computer? Since viruses frighten most us, it is smart to implement some preventative measures as soon as possible. For you to accomplish that, you should know there are many computer viruses present in the cyber world.

In this article, we will tackle the topic about computer viruses and the different. This will help your device especially in the long run as virus programmers are developing stronger viruses that have a stronger possibility of penetrating computer systems worldwide.

Furthermore, when we discuss things that relate to computer security, the virus is the most prominent threat. It can destroy a small part of the system or the entire system. The first recorded virus was formed 4 decades ago and is known as the “creeper virus”, which inflicted damage on ARPANET. Three decades ago, the earliest virus that spread was formed and multiplied by floppy disks.

More than half of the threat that targets computer systems is viruses. Not all are viruses, some of them are adware, malware, Trojans, and worms that can also inflict damage. Recently, viruses grew in number, which is critical for device owners and the performance of the computer. Due to recent creation of many viruses in developments worldwide, it has made it trickier to detect and remove. Thanks to modern antivirus software end-users can minimize the damage a virus can cause resulting in a better computing experience.

Resident Virus

Can be found in RAM and is a common type of computer virus. It installs malicious code into the memory results in the damage of data and apps. Manipulation of MBC (memory control block) is a technique used to spread this virus. The most known resident viruses are Meve and CMJ.

Multipartite Virus

This can quickly spread in your entire OS. It spreads when an infected computer is booted, executing unpermitted activities in your OS, in folders, and other apps on your PC. It attacks both boot sector and .exe files.

Direct Action Virus

This type of virus targets certain types of files, usually executable files. The primary use of this virus is to damage the files in folders. However, it does not usually remove files or influence the performance of the computer. It can be quickly taken away by antivirus software.

Browser Hijacker

This kind of virus targets your browser in which it will redirect you to a different site. When a web address is typed in the address bar, the attack causes several fake sites to open that may infect your computer. Reliable browsers have integrated features to block them ahead.

Overwrite Virus

From the name itself, this virus replaces the content of a file, losing the original content. It removes the original program code by overwriting the data in system memory. It targets the files that can be found on your computer.Because it destroys the original file, to disinfect the device of the overwrite virus, the complete file must be removed and restored from a backup.

Web Scripting Virus

This virus breaches your browser security. These might have harmful scripts that if clicked, the virus will force and infected code and inject client-side scripting on the web page. This redirects you to a malicious website or downloads automatically on your device.

Boot Sector Virus

This usually infects floppy disks or the master boot record (MBR). They became present when floppy disks were needed to boot a computer. Once infected, boot sector viruses try to infect every disk opened on the infected system.


This infects apps and software that have macros, like Excel. It causes ill-effects such as causing poor performance of the app. Relax is an example of a macro-virus.

Directory Virus

This type of virus usually alters file paths.When you execute apps that have directory viruses, this virus also executes itself secretly.Moreover, it might be hard for you to pinpoint the original application once it is infected by the virus.

Network Virus

This virus spreads on the LAN and the internet.It replicates through computer systems drives and shared resources.SQL slammer worm is a worm that caused a DOS on some Internet hosts and radically slowed down Internet traffic, in January 2003. It spread rapidly, infecting 75,000 victims in 10 minutes.

Nonresident Virus

Modules are the primary medium of this virus as they spread immediately on them. When there is a running module, it will choose the files that it is planning to infect.

Stealth Virus

They usually deceive antivirus programs by pretending to be genuine files or programs and send redirecting commands to the operating system. Some antivirus apps cannot locate them. There are instances when stealth virus has hidden within the computer system to avoid deletion.

Sparse Infector

This virus uses different strategies to lessen the chances of being detected. It schedules their attack of a program.It infects files when certain conditions are met. Example, a virus which infects only the 40th time a file is executed would be a sparse infector.

Space Filler Virus

Also know at the “Cavity Viruses”. They bond themselves to the file and make significant changes to the boot of the program or encrypted code. They also do well-executed methodologies, so you will not know the heightened number of file code.

Polymorphic Virus

They use a unique way whenever they target a system.With this antivirus that you have may have difficulties to find them even on a deep scan.It alters its signature pattern whenever it replicates.

File Infector Virus

This virus also targets the .exe and .com program files.When you execute them, you will give way for the virus to start its attack.A huge number of viruses that we know fall into this category.

Companion Virus

This type of virus must always have a partner virus for it to be effective.When that file is executed, the virus will infect the computer and remove files on your computer hard drive.Some examples of this are the Asimov.1539 and Stator.

FAT Virus

Typically, this kind of virus damages the sectors where you can find the data stored on the hard drive.

Encrypted Virus

It uses encrypted malicious codes with the ability to hide from the antivirus definitions.Each time it infects, it automatically encodes itself differently, so its code is never the same.

An encrypted virus encrypts its payload with the intention of being undetectable.All files that are encrypted require a decryptor or a key an antivirus can use as the decryption method of detection.

Other Types

These unpopular infections are not considered viruses, but they also resemble viruses.This includes of Trojans and malware.

What are Trojans?

It is also a kind of malware (malicious software) which is used by hackers to gain access to computer systems. A Trojan or Trojan horse is a type of malware that conceals its true content to fool a user into thinking it's a harmless file. An example is the commonly known trojan, Backdoor Trojan. It allows hackers to remotely access and control a computer.

Above are some of the different types of viruses that you might encounter on your computing journey. No one wishes to seethese on their device due to the possibility of significant damage they cause when comingling with their entire computer system. It is important that you take preventive measures in hopes you never experience a virus, trojan, or malware attack on your device. Until, next time, remember to always think security first!



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