Various Types of Computer Viruses
You start up your computer for another fun, productive day. Suddenly you notice that your computer is running more slowly than usual. It doesn’t appear to work quite like it used too. After checking with other members of the household that may have used the computer, no one claims responsibility for using the machine since you last turned it off. Thinking back, you recall that you did not install any new programs or make any changes to the configuration. Confident that it isn’t something that was purposely done, the fearful thought of being infected with a computer virus enters your mind. This begs the question then, what exactly is a computer virus? To put it bluntly, a computer virus is any program on your system that does something unexpected or unplanned.
A computer virus doesn’t just appear automatically. Someone, somewhere, at some point in time had to write a program or perform some computer action that makes something happen. While most people define a computer virus as something that is harmful, it actually consists of any type of computer instruction that occurs without someone desiring the action to happen. The severity of the virus can range from being completely harmless running without notice, to annoying pranks, or being completely destructive that will cause data loss or hardware failure. While there are people that do create viruses with the intent of doing harm, most viruses are created by people accidentally. Beginning programmers are trying to learn some type of programming task or inadvertently performed a harmful action.
There are a few different flavors of viruses. Each one has a specific agenda to perform. The most common categories include worms, trojans, bimodal/bipartite, macro, boot sector, executable and polymorphs. Although the terms sound pretty sophisticated, they are actually pretty simplistic in nature. All of them work in a similar fashion such as do viruses that affect humans. After infection, the virus strives to keep itself alive. Some methods this is done is by mutation and spreading to other systems. A computer virus has to have a source. A transferred file or an action that was implemented by someone can result in an infection.
Understanding how the virus types work helps to reveal their severity. A boot sector virus triggers as you are starting your computer. It embeds itself into your computers’ booting hard drive code and changes the way the computer starts up. These types of infections are extremely difficult to remove. Executable and macro viruses are the most common types of viruses and can spread easily. These viruses are only triggered when you run a program that in turn causes the virus to execute. They cannot be triggered to execute on their own. Each of these can cause your computer to run strangely. In addition, they are easily transferred when sharing files, sending emails and browsing the Internet.
Trojans and worms tend to be more severe computer virus infections. These infections are the ones that make the nightly news. Both have the ability to run on their own without the help of another application. Trojans are the favorites of hackers as they can be used to take control of other peoples’ computers and can cause major damage. The main purpose of worms is to copy itself onto another machine. These types of files like to take advantage of computer networks and tie up the bandwidth. This in turn prevents valid data from being transported over the cable. Bimodal/bipartite and polymorphs are special categories of viruses. Like the prefix suggests bimodal/bipartite are two viruses in one. They are a combination of a boot sector and executable virus. Polymorphs are the most difficult type of virus to detect. Eradicating them is hard as they are constantly changing and evolving. Virus detection programs look for specific types of computer code and the executable code changes makes detection difficult.
Now that you have some awareness of what computer viruses are, use this knowledge to fight these infections. Just as you don’t feel well when you acquire a germ, the computer doesn’t like having unwanted code running on it. Make sure you have good quality security software and keep it updated. Once acquired, some viruses can be quite difficult to remove. This process can result in data loss and can be expensive. Avoid the discomfort and keep your system protected.