A computer virus is any malicious program that has the ability to replicate itself and perform destructive activities on any device or network. Viruses can infect computers and destroy the data present in the drives by inserting their malicious code. If the virus continues to spread quickly, it can even cause the device to crash.
Identification of a virus:
Each year, computer viruses cause damage worth billions of dollars to the relevant industry. Because the virus affects the programming of the system, it is invisible to a normal user. However, some key indications can help you in identifying computer viruses. Some of the signs that your system is under virus attack are highlighted below:
- The system processing becomes slower, and it takes a lot more time for the applications to open. Normally, this is the first indicator of a virus spreading in a device.
- Some files and applications open in the background without the user’s actions.
- Too many pop-up windows might start appearing on your screen.
- There is an increased likelihood that you will be automatically signed out from your social media accounts in case of a virus attack.
- In the majority of cases, once the virus spreads out of control to almost every file and application in the system, the device may crash and cease to work altogether.
Different types of Computer Viruses:
A computer virus comes in many types with each having the potential to cause substantial damage in a unique way. Following are some of the most common types of computer viruses:
Direct Action Virus:
It is a type of virus that directly attaches itself to a file with a .com or .exe extension. It is also known as a “Non-Resident Virus”.
Boot Sector Virus:
When a virus spreads to and infects the floppy drive’s boot sector or Master Boot Record (MBR) of hard drives, it is called a “Boot Sector Virus”. Since floppy drives are non-existent nowadays, these viruses commonly spread via USB or hard drives. This virus is particularly troublesome since the boot sector contains the files needed to kickstart a system’s operating system.
Unlike the Direct Action Virus, this type of computer virus doesn’t attach directly to a file but rather saves itself in the memory and can quickly spread to other files and programs.
A Multipartite virus is extremely dangerous since it possesses the properties of both the Boot Sector and Direct Action Virus. This type of virus can simultaneously infect the boot sector and executable files of a system. It is also known as a “Hybrid Virus”.
Arguably the most harmful one in the class of computer viruses, an Overwrite Virus has the potential to replace the existing program with a malicious piece of code. Slowly, the malicious code overwrites the existing code of the program to render it useless.
A Polymorphic Virus can evade the antivirus installed in the host device by periodically changing its name. It infects various files and functions of a system and tricks the computer into believing it’s a new file to evade detection.
This type of virus spreads through word processing software such as Microsoft Excel and Word. Macro Viruses generally spread when an infected document is shared via email and then opened in the host device where it starts spreading to other files.