Q: What is a virus?
A. A virus is a piece of code that uses a computer's resources to spread, replicate, and extract private information from your computer. The replication occurs without the user's knowledge.

Q. How does my computer get infected by a virus?
A. Different viruses have different ways of infecting a computer or floppy disk. Infection can occur if you start your computer from an already infected disk, use an infected file or application on your computer, or use your disk in an infected computer that then spreads the infection to your disk.

Q. What are the most common types of viruses?
A. The most common type of virus currently is the macro virus. The second most common is the boot sector infector. Other common viruses that infect applications are called file infectors. Most viruses now prevalent are one of these types or are a combination of them.

Q. What is a macro virus?
A. Any virus that uses "higher level" programming features can be considered a macro virus. Previously, many viruses were created using lower level system code to infect and damage computer files. Occasionally, viruses would be created using macro language tools, but the tools were not very powerful or flexible. Viruses were hard to create.  To allow users the ability to write custom routines (macros) in applications like Word and Excel, Microsoft included with these applications a version of Visual BASIC, a "higher level" programming language that was powerful and easy to use -- and easy to create viruses with.
The prevalence of Visual BASIC and Microsoft Office means that most macro viruses affect either Word or Excel. There are other macro viruses written for non-Microsoft Office products but they are a small number in comparison.

Q. What is a boot sector infector?
A. A boot sector infector is a virus that exists in the bootstrap record of a floppy or hard disk. It loads into memory when the computer is "booted" from an infected disk. Boot sector infectors spread when you access a writable floppy disk from an infected computer. The infected copy then becomes a carrier for the virus. The virus is spread to other hard drives when an infected disk is used to start up the computer. This happens most often when a floppy disk is left in the disk drive of a computer and then the computer is turned on or rebooted.

Q. What is a file infector?
A. A file infector is a virus that attaches itself to, or is associated with, an executable file. An executable file can be a program file, like Word or Excel, or a system file, like command.com or the Macintosh's Desktop file or Finder. A file infector spreads when an infected executable file is run; other application files that are run subsequently then become infected. The infection can also spread to executable files, which are run from writable floppies on an infected computer. The infection is usually spread to other computers by sharing infected executables.

Q. What does antiviral software do?
A. Antiviral software attempts to prevent, detect, and remove viral infections. There are three ways in which antiviral software attempts to do this: activity monitoring, change detection, and scanning. Most antiviral software uses, or makes available, all three. TCI supported / recommended antiviral software is McAfee which offers the ability to use all three types of strategies to combat viruses.
Activity monitoring does what the name implies; it monitors your computer for any activity that is "virus-like." When it detects this activity it can either notify you of the activity, so that you can determine if it is "legitimate" activity or not, or it may prevent the activity until the monitor is "turned off." This allows you to keep track of activity that you may not be aware of and to determine whether you want the activity to continue or be prevented.
Change detection monitors your system against a previously saved "snapshot" of your system to determine if anything has changed. Common areas that are frequently checked this way are the memory map, what is loaded into memory and where it is, and executable file sizes. More often than not these items are relatively static and most unexplained changes should be investigated.
Scanning is the lynchpin of most antiviral software. Scanning checks your system against a listing of code in known viruses, called "signature scanning." When a signature is discovered the application notifies you of the possible presence of a virus.
These strategies have flaws, but when used in combination they are usually very effective.
The key to making sure your system is virus-free is to use antiviral software and keep it up to date. Old software is not, and cannot be, aware of new viruses.

Q. I think that my system may have a virus but my software doesn't detect it. My friend's software package detects a virus but my antiviral software doesn't see anything. What should I do?
A. If you think that your system has a virus, don't panic. Make sure that you have the most current version of antiviral software. If one package sees something that another doesn't, make sure that both packages are up to date. If you are using the current version of antiviral software and it still doesn't see anything, contact TCI and we will be glad to assist in getting your computer(s) back on track.

Q. How can I tell if my computer has been infected by a virus?
A. Your system may have a virus if you notice odd or unreliable behavior with your computer. This doesn't "prove" that your computer is infected, but it does indicate something that needs attention and perhaps intervention. Often the search for an infection leads to finding corrupted or damaged files or applications, or even incipient system problems, which have nothing to do with a virus infection. You know your computer better than anyone else, and if it begins to operate in a way that seems "wrong" to you, you should start investigating.

Q. What are common symptoms to look for?
A. Symptoms of an infection vary depending on the type of virus you have, but there are some general guidelines. A common symptom of a boot sector infector is problems with booting: the system doesn't boot or displays odd messages when booting. Your software may note a change in the boot sector or memory map.
Symptoms of file infectors can be executables that used to work but are now failing to load correctly. Your antiviral package may indicate that something "goes resident" in memory and stays there after running an application.
A macro virus infection is usually not as subtle as file infectors or boot sector infectors. With a macro virus all your documents may only offer you the option to save them as templates. You may notice "extra" macros that did not come with your word processing package and that you did not create.
As soon as you note a symptom, investigate! You may not have a virus, or even a serious problem, but don't take chances.