Computer Virus and its types
A computer virus is a kind of malicious computer program, which when executed, replicates itself and inserts its own code. When the replication is done, this code infects the other files and program present on your system.
These computer viruses are present in various types and each of them can infect a device in a different manner.
In this article, we shall discuss in detail what is a computer virus and what are its different types
What is a Computer Virus?
A computer virus is a program which can harm our device and files and infect them for no further use. When a virus program is executed, it replicates itself by modifying other computer programs and instead enters its own coding. This code infects a file or program and if it spreads massively, it may ultimately result in crashing of the device.
Across the world, Computer viruses are a great issue of concern as they can cause billions of dollars’ worth harm to the economy each year.
Since the computer virus only hits the programming of the device, it is not visible. But there are certain indications which can help you analyse that a device is virus-hit. Given below are such signs which may help you identify computer viruses:
- Speed of the System – In case a virus is completely executed into your device, the time taken to open applications may become longer and the entire system processing may start working slowly
- Pop-up Windows – One may start getting too many pop up windows on their screen which may be virus affected and harm the device even more
- Self Execution of Programs – Files or applications may start opening in the background of the system by themselves and you may not even know about them
- Log out from Accounts – In case of a virus attack, the probability of accounts getting hacked increase and password protected sites may also get hacked and you might get logged out from all of them
- Crashing of the Device – In most cases, if the virus spreads in maximum files and programs, there are chances that the entire device may crash and stop working
The first thing which you might notice in case of virus attack is the speed with which your system shall process. And then gradually other changes can also be observed.
Types of Computer Virus
Discussed below are the different types of computer viruses:
- Boot Sector Virus – It is a type of virus that infects the boot sector of floppy disks or the Master Boot Record (MBR) of hard disks. The Boot sector comprises all the files which are required to start the Operating system of the computer. The virus either overwrites the existing program or copies itself to another part of the disk.
- Direct Action Virus – When a virus attaches itself directly to a .exe or .com file and enters the device while its execution is called a Direct Action Virus. If it gets installed in the memory, it keeps itself hidden. It is also known as Non-Resident Virus.
- Resident Virus – A virus which saves itself in the memory of the computer and then infects other files and programs when its originating program is no longer working. This virus can easily infect other files because it is hidden in the memory and is hard to be removed from the system.
- Multipartite Virus – A virus which can attack both, the boot sector and the executable files of an already infected computer is called a multipartite virus. If a multipartite virus attacks your system, you are at risk of cyber threat.
- Overwrite Virus – One of the most harmful viruses, the overwrite virus can completely remove the existing program and replace it with the malicious code by overwriting it. Gradually it can completely replace the host’s programming code with the harmful code.
- Polymorphic Virus – Spread through spam and infected websites, the polymorphic virus are file infectors which are complex and are tough to detect. They create a modified or morphed version of the existing program and infect the system and retain the original code.
- File Infector Virus – As the name suggests, it first infects a single file and then later spreads itself to other executable files and programs. The main source of this virus are games and word processors.
- Spacefiller Virus – It is a rare type of virus which fills in the empty spaces of a file with viruses. It is known as cavity virus. It will neither affect the size of the file nor can be detected easily.
- Macro Virus – A virus written in the same macro language as used in the software program and infects the computer if a word processor file is opened. Mainly the source of such viruses is via emails.
Blog By: Sumit Bhaduriya