Computer viruses – 5 Types of Computer Viruses you should know
The term Computer virus is common to a lot of people especially those in technologically advanced countries and those who have devices like laptops, or handsets that are prone to viruses.
A virus is malicious software that attaches itself to a program or computer file and when executed, replicates itself and alters other program’s data. There are several ways through which virus can gain access to one’s device and some of them are:
- Infected Diskettes: A virus can attach itself to your computer once you insert an infected diskette inside of it and try to open or execute a file on it.
- Sales Demo Disk: A virus might be attached to a demo of a product and once you do not renew the license, the virus attached to the demo would automatically start corrupting files on your system.
- Infected Emails: Not all emails you receive are good emails, some are sent by scammers or phishers and once you click on a link attached to the email, then the virus would attach itself to your system.
- Infected Computer: When the Hard disk of a computer is infected, then the whole computer is likely to get infected because most of the files being used in a computer system are stored in the Hard disk drive.
- Downloading from Unknown sources: Some sites where people download files containing a lot of malicious software’s and during the download, the virus would attach itself to your computer without your knowledge.
The above mentioned are some of the most common ways by which virus can transfer so ensure that whenever you use a new device on your system, you scan it with antivirus software also avoid downloading files from unknown sources.
Finally, avoid trial versions of softwares that you know nothing about because some of them can attach viruses to them without your knowledge and once you fail to renew the license of the software at a particular time,
Below is a list of the most common types of Virus:
- BootSector Virus: Boot sector virus is a virus that attaches itself to the boot sector or the partition table of a disk. Before you understand what a boot sector virus is, you would have to know the definition of boot sector and a boot sector is the sector of persistent data storage that contains machine code to be loaded into the RAM and then executed by a Computer’s built-in firmware. Boot sector viruses are mostly obtained from an infected diskette left in the drive when the computer is booting or some file infectors can drop it. Examples of boot sector viruses are AntCMOS and AntiExe.
- File Virus: File viruses are those files that attach themselves to executable files and these viruses work by locating the type of files they know how to infect and examples of such files are .exe, .vbs, and .com files respectively. Once the file is executed, then the virus would enter the computer memory and run the computer down.
- Multipartite Virus: A multipartite virus like the name implies is a virus that has a dual personality and it is a virus that infects your boot sector as well as files. In addition to the definition given in the first point, the boot sector is that area of your hard drive that is accessed when the computer is first turned on. There are types of Multipartite virus and some of them include stealth, and polymorphic virus respectively.
- Logic Bomb Virus: A logic bomb virus operates using the principle of operation of a logic bomb. The logic bomb virus is one that executes malicious functions whenever a logical condition is met and some of the logical conditions include deleting of files, and they behave like bombs.
- Trojan horse: Trojan horse got its name from the Ancient Greek city that was destroyed by a horse crafted to hide enemy solider of which one of them was Achilles. It attaches itself to the middle of a program and once the program is run, the program goes to work doing its damage. In simple terms, a Trojan horse is one that masquerades as another common program in an attempt to receive information.
The world of computing is very dynamic and the number of viruses might have increased over the years and some of them are Macro virus, Browser hijacking, Web scripting virus, and resident virus respectively. The number can increase as more discoveries are made so ensure that you are up to date.