A computer virus is a program designed to perform malicious actions which spread one computer to another computer by itself without the user’s acknowledgement. In this post, we will discuss on common types of virus on computer and how to protect them to ensure cyber security.
Computer virus can spread through different ways such as removable media, downloads software, visiting vulnerable website, clicking on infected advertisement and e-mail attachments.
Table of Contents
Types of Virus on Computer
It is very important that, you should know the computer virus and its type to protect from malicious attacks. There are different types of virus on computer, which are as follows:
Boot Sector Virus
Direct Action Virus
File Infector Virus
Web Scripting Virus
1. Boot Sector Virus
A boot sector virus is types of virus on computer or malware that infects the boot sector of floppy disks or the Master Boot Record (MBR) of hard disks.
MBR is a small program and first sector of the computer hard drive that identifies how the hard drive is partitioned and how to load the operating system. The MBR executes every time the computer starts up and its controls the boot sequence.
This type of virus is activated every time when you start your computer and take control when you start or boot your computer.
Examples: Some examples of Boot Sector Virus are: Form, Disk Killer, Michelangelo, and Stone virus
How Boot Sector Virus spread
The boot sector viruses usually spread via infected physical media such as a floppy disk or USB drive.
Boot sector virus also infected by malware if you downloaded malicious software or received via email attachments.
However, the boot sector viruses essentially accomplish the following way:
The virus can overwrites or copies the master boot program to another part of the hard disk.
The computer can infected when it boots up or accesses the infected floppy disk
Finally, generate bad disk sectors
How to get rid of Boot Sector Virus
It is very difficult to removing a boot sector virus from computer because it may encrypt the boot sector.
However, the best way to get rid of the boot sector virus is to use antivirus software. There are also some specific tips that relate directly to boot sector viruses.
Example: Some popular resident viruses are CMJ, Meve, and Randex.
HowResident Virus Spread
Suppose, a user running multiple programs at the same time for his personal reasons.
If Resident Virus actives and the user open a program (i.e., PowerPoint) then the virus will infect all those running programs.
How to remove a resident virus
Here are the some simple steps to find out and remove the resident virus from your computer.
Go to Strat -> Type Task Manager and Click on the Process Tab
Find out the Resident Virus and Click on End Task
Go to Strat -> Type “regedit” and Click on Yes for “Registry Editor”
Now, expand the “HKEY_LOCAL_MACHINE” and press “Ctrl+F”, then type a Resident Virus name
Delete the suspected files by right-clicking
4. Macro Virus
A macro virus is types of virus in computer which is written by macro language such as VBA. The Macro virus spreads one computer to other computer through software applications programs such as Microsoft Word, PowerPoint and Microsoft Excel .
The Microsoft Word and Microsoft Excel are two most popular applications programs which are capable of executing macros.
When a macro virus infects an application program, then it can create new files, move text, corrupt data, send files, and insert pictures.
How do spread macro viruses?
Macro viruses are spread whenever you open an infected file or document. However, here is the most common ways that macro viruses can spread:
Through phishing emails
Sharing files on a disk or a Network
Download and opening an email attachment file
Downloading and opening a file from internet
How to Get Rid of a Macro Virus
In order to get rid or protect from macro virus you should use antivirus software. There has professional anti-virus software such as Norton, Bitdefender, Kaspersky, Panda, ESET, Avast, AVG. So, you can use one of them and keep updated with update version.
5. Multipartite Virus
A multipartite virus is special types of fast-moving virus on computer that can attack both the boot sector and the system or the program files at the same time.
This type of virus can spread by performing unauthorized activities on your operating system, files, folders, and programs.
How to avoid Multipartite Virus
It is very difficult to detect and remove the Multipartite Virus from your computer because it spreading very fast. However, here are the some tips on how to avoid any types of computer virus and the multipartite virus also.
Install a trusted anti-malware software
Never open and download email attachments from a nontrusted source.
Update the antivirus software
Scan the file and document using antivirus software
6. File Infector Virus
A File Infector Virus or File Infector is types of virus on computer that infects executable files (.exe) of programs and operating systems (Windows, UNIX and Macintosh). This type of virus overwrites the existing code or inserts infected code into an executable file.
File-infecting virus formatting the hard drive, damages or slow down the programs or makes them unusable and overwrites the host files.
How to spreadFile Infector Virus
If you run a program which has been infected by that virus, then the Virus can replicate the malicious code to other applications. It can also replicate and spread through the entire system and over the network.
7. Browser Hijacker
A browser hijacker is unwanted software that modifies web browser settings without the user’s permission and automatically redirect to a malicious websites.
If you enter a domain name or website address in the web address bar, then the browser hijacker will open multiple vulnerable websites and may damage your computer.
Some common examples of Browser Hijacker are: GoSave, Ask Toolbar, RocketTab.
A polymorphic virus is a complicated types of virus in computer that changes their code and their appearance every time and infects a new file of a computer. The polymorphic virus duplicates by copies of itself, creating new or modified the code.
It’s frequently changing identifiable characteristics such as file names, types or encryption keys. So, it is very difficult to detect them by using anti-malware program.
How to protect from Polymorphic Virus
However, here are the few important tips for protecting from Polymorphic Virus:
Keep Your Software Up To Date
Never Click on Suspicious Links
Use Strong Passwords and Change Regularly
Use professional anti-virus software
9. Web Scripting Virus
A web scripting virus is other types of computer virus security vulnerability that breaches your web browser security. In web scripting, the attackers can inject client-side scripting into the web page and take access controls in order to steal sensitive information from web browser.
This web scripting virus exists in website content such as image, ads, videos and URL links. When you click on that linkable content, the viruses will be automatically downloaded malicious programs or will redirect to you to vulnerable websites.
How to prevent web scripting viruses
Here are the helpful tips for prevent from web scripting viruses: