A computer virus is a small program that infects your computer and replicates itself to distribute to other computers. The internet connects so many computers, and we often share files with others, that a virus can quickly spread from computer to computer unknowingly. Depending on the virus the effects can be devastating, from deleting or corrupting files to disabling security so that you are left vulnerable to a hacker.
Types of Viruses
There are many categories of computer viruses. These are just the six most common. The first is resident viruses. These are viruses that hide in your RAM on your computer controlling or intercepting operations. Most often these viruses are used to capture passwords or credit card information, and can corrupt programs or files.
The second type is direct action viruses. These are viruses that take direct action and replicate when they are run. When certain conditions are met, the virus becomes alive and begins replicating itself. It will generally attach itself to files on your computer so that when the file is run the virus is activated. These files can be recovered using anti-virus software.
The third type is overwriting viruses. These viruses delete the information for a file then copy themselves into the file. The only way to get the file back is to get it from a previous back up.
The fourth type of virus is the boot virus. This type of virus infects the boot sector, or the part of the hard drive that stores basic system information and is used to start up your computer. When the computer is booted up, the virus activates.
The fifth type of virus is a macro virus. These viruses hide out in macro files, or mini programs used to help you in Microsoft Word, Excel, Access or PowerPoint. When you run the macro in its respective program, the virus runs as well. Finally, there are file infectors. These are viruses that infect your executable files or programs. Each time you run the program, the virus is activated.
If You Think You Have a Virus
…don’t panic! You can probably fix the problem quite easily with anti-virus software. If your computer is acting funny, booting slowly, having a lot of errors or giving you lots of pop-up windows, you probably have a virus.
As soon as you suspect you have a virus, stop what you are doing and close everything you have open. Run your antivirus software to make sure it is working. Update your virus definitions and run it again to be certain there are no viruses lurking in your computer. If your computer is still messing up and you don’t come up with any viruses, check it for spyware. If your antivirus software does come up with a virus, simply follow the instructions on your screen to get rid of it.
When You Can’t Use Antivirus Software
Sometimes antivirus software is not allowed to run by a virus. You have three options if that happens. You can use an online antivirus scan to find and destroy the virus. You can use a rescue disk created when you first installed the antivirus software. Instructions for how to use the disk should come up when you insert the disk and run it from the drive. Finally, you can remove your drives, install them on another pc or network, and use another computer to scan and fix the drives.