Computer Virus: Everything To Know in 6 Easy Points

In this article let us look at:

  1. What is a Computer Virus?
  2. Types of Computer Viruses?
  3. How does a Computer Virus Attack?
  4. How do Computer Viruses Spread?
  5. What are the signs of the presence of a Computer Virus?
  6. How to protect against Computer Viruses?

1) What is a Computer Virus?

Just like a flu virus, a computer virus is programmed to spread from one host to another host and can replicate itself. A technical computer virus definition would be, it is a malicious program or code that is written to change the way a computer works and spread from one computer to another.

When this written code is executed, it modifies the pre-designed programs that support macros and inserts its code. The damage caused by a virus is unexpected; it can corrupt the system software or destroy data. So this explains what a computer virus does and how it affects your device. Now let us move to its types and know about computer viruses in greater detail which will help us to stay cautious and prepared in case of a virus attack!

2) Types of Computer Viruses?

There are different types of computer viruses. These are mentioned below:

  • Boot sector virus: This virus can take control of your system when you start or boot it. It can spread by inserting an infected USB drive without scanning into your system.
  • Browser Hijacker: This virus hijacks some browser functions and you may automatically be redirected to some unintended website.
  • Web Scripting Virus: This type of computer virus will exploit the web browser and web page codes. When somebody hits such a website, the virus may infect his computer.
  • Resident Virus: It is a general term for any virus residing in the computer memory. It can act anytime when the operating system boots up.
  • Polymorphic Virus: This virus changes its code every time a file infected with a virus is executed.
  • File Infector Virus: This virus puts malicious code in the executable files.
  • Multipartite Virus: There are multiple ways in which this virus can infect and spread. It may infect both system sectors and program files.
  • Macro Virus: This type of virus is written in the same macro language as software applications. It spreads when the infected document sent generally by email is opened.

3) How does a Computer Virus Attack?

Since now you know what a computer virus and its types are, let us discuss how a virus attacks your device and its effects. After post successful introduction of a computer virus through a document, file, or program into your device, it lies quietly into your system until circumstantially its code gets executed. Once that particular file is executed it leads to the execution of the virus code thus infecting the system as well.

Once the computer gets infected, what does a computer virus do depend entirely on the features of the computer virus? Some viruses can be playful while others can cause deep damaging effects.  But the thing about computer virus is, if it has infected your computer, it can replicate on all the computers on the same network thus verifying the computer virus meaning.

Some of the examples of effects of computer virus are: it can steal data or passwords, log keystrokes, spam your email contacts, corrupt files, erase data, cause permanent damage to the hard disk, and sometimes can even take over your device control. Some devastating viruses are designed with the sole motive of financial gains.

4) How do Computer Viruses Spread?

How can you catch a computer virus? In this technology-driven world, there are many major sources of computer virus spread. It can spread through text messages and email attachments, social media, and e-file downloads. Your smartphones can get infected via malicious app downloads. Other prime causes of computer virus spread include viruses hiding behind socially shareable posts like greeting cards, AV files, and funny images.  This explains how does a computer virus spreads and causes severe damage to a device.

The only way known for computer virus prevention is to stay cautious while being on the internet. Practice extra caution while opening attachments or links and downloading files. Do not download email or text attachments from suspicious websites.

5) What are the signs of the presence of a Computer Virus?

Just like the flu virus starts showing symptoms when it infects the human body, similarly, the presence of a computer virus can be felt with a variety of symptoms. Some of the symptoms that explain computer virus presence are:

  • Homepage changes: You may notice that the web-browser homepage changes to another website automatically. Also, it will be difficult to reset it again.
  • Frequent window pop-ups: Some characteristics of a computer virus will produce unnecessary pop-ups and encourage you to visit unintended websites.
  • Mass emailing from your email address: A person can take over your email id or may send mass emails in your name from different infected computers.
  • Frequent Crashes: As you know how a computer virus works on certain hard drives. They may cause major damage and result in device getting freeze frequently. In some worst cases, the device may not switch on again.
  • Slow computer performance: If your device has gone down slow suddenly, this could define computer viruses present in your system.
  • Unknown programs running on your system: You might have noticed some unknown programs popping up when you start up your system. Or if you look at the list of active applications you find some unknown application, this is sure information about computer virus presence in your device.
  • Strange activities like password change: As the definition of a computer virus says, it can modify a legitimate program. So if the virus code changes your password, it will prevent you from logging into the system.

6) How to protect against Computer Viruses?

How do you prevent your device from different types of computer viruses?  Here are the following ways by which you can prevent the virus from infecting your devices:

  • Keep trusted antivirus software on your computer. Do not forget to update it promptly. Do not miss the update notifications to keep your device safe.
  • Do not forget to scan an email attachment before opening it.
  • Do not click on unnecessary pop-up advertisements as these may lead to unintended websites that may cause harm.
  • Do not insert an external device like pen-drive, CD, etc without scanning it with antivirus software.
  • As the computer virus definition says, the computer virus may remain hideous unless the virus code is run, it is better to scan files that you download through file-sharing programs.


However vigilant you remain, there could be a scenario where you will need to deal with a computer virus. There are two ways by which you can remove a computer virus. First is the manual approach and the second is with the help of an antivirus program.

In the former approach, you need a little expertise on what is a computer virus and what are the types of computer virus. Which one has infected your system? You need a lot of web search and this approach may take time. If you need an easier approach go with the second one. Download antivirus software and kill the damn virus! This software will protect you from future threats as well.

In case, you are interested in Cyber Security then browse through our Master Certificate in Cyber Security (Blue Team), a 520 hours long program with preparation for 7 global certifications.

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