- Internet & the Web
What are Computer Viruses?
Definition of a Computer Virus
A computer virus is a malicious program that is designed to do bad things like delete files or consume your computer’s resources. Viruses often duplicate themselves and infect other files on the same computer and may be spread through email attachments or type of network activity.
The Most Common Types of Computer Viruses
Boot Sector Virus—these are not as common as they used to be since they are primarily spread through floppy disks. Boot sector viruses hide in the boot sector and load into memory whenever your computer boots up.
Logic Bomb Viruses—also known as a “time bomb”, it inserts itself into other programs to perform a specific action when a particular condition is met, such as a specific date and time. Once the condition is met the logic bomb virus will perform some malicious activity such as deleting files, displaying unwanted messages, or disabling programs on your computer.
Macro Virus—these are usually spread through Microsoft Word or Excel through email attachments. Macro viruses will run automatically when the infected file is opened. They usually are not too damaging though.
Worm—is a type of virus that will replicate itself over and over. It will consume some or all of your computers resources, including hard disk space and memory. Worms typically make your computer run very slow.
Other Types of Harmful Programs
Malware—is a broad term for all types of harmful software listed here, including viruses, Trojans, worms, and spyware.
Trojans—technically this is not a virus, it is another type of computer program designed to do bad things to your computer.
Scareware—is designed to trick someone into purchasing software that is potentially dangerous. The software will claim your computer is infected with a virus or spyware and ask you to purchase software that will fix the problem. Usually the software that is purchased is spyware or some other type of malware.
Spyware—is software that spies on your computer. Spyware can capture email messages, user name and passwords, credit card numbers. The software will usually pass the information it collects to another computer on the Internet.
How to Protect Yourself from Computer Viruses
- Use a modern operating system. If you are still using Windows 98 or ME, it is time to upgrade to at least Windows XP, preferably Windows 7 if your computer is fast enough to run it.
- Install the latest security patches from Microsoft. Turn on Automatic Updates is the easiest way to do this.
- Install Antivirus software from a reputable company and keep it updated with the latest virus definitions.
- Don’t open email attachments from people you don’t know. It is a good idea not to open email attachments from people you do know without asking them first if they sent it, especially if you were not expecting an attachment from them.