Computer Virus Information
Web-based classes involve sharing, uploading, and downloading software that, when infected with viruses, might be harmful to the entire system. Therefore, some simple actions will be required from you in order to prevent computer viruses and other forms of destructive software.
What is a computer virus?
- A computer virus is a program that is able to modify the behavior of an executable at run time, making a copy of itself possibly each time the file is executed.
- Note that any program needs only to multiply itself in order to be considered a virus.
- The virus program carries a set of instructions that triggers them to activate.
- A computer virus is a computer program, just like any other. However, it has the ability to do nasty things. Most computer viruses can copy themselves into different software when an executable program is running.
- The term computer virus came from the analogy of a biological virus. Like a biological virus, a computer virus has the activation and the replication process. The activation process depends on the type of virus, but usually it takes place when a host program is running. A host program is a larger program in which the virus has resided.
- The replication process occurs right after the activation. It is in the replication process that the virus "looks" for other host programs or copies itself to the system disk or diskette being used.
Where do viruses come from?
- Since a virus is just a computer program, a virus can be produced by anyone that has some computer programming knowledge.
How can my disk or computer get infected? A hypothetical situation would best explain one of the most common forms of viral infection:
- A classmate from your online class was "surfing" the net and found a very good informative piece of software that can be used for the class. He decided to download the software and put on his home page without scanning the software for viruses. The next day he announced to all the distance learning participants that they should try to use the software.
- Then, all the students downloaded the software and installed it on their home computer.
- After installing and running the software at home, some of the students typed a spreadsheet or report saved it to a disk and took it to work.
- As the software downloaded by the classmate was infected by a virus, all the students' computers, including those at work, would be now infected.
What can I do to keep my system safe?
Because different types of viruses are continuously being engineered, there is no way of keeping system 100% safe. The good news, however, is that you can take a few, easy steps to prevent virus to a maximum extent.
- Keep backups of all you important data.
- Scan your disk and your system periodically with an efficient anti-virus program
- NEVER assume the software you are downloading is safe, even if the file comes from a instructor or organization.
- NEVER run an executable program, if you have not previously scanned it for viruses. Some viruses manifest themselves as an interactive program, and even ask you to do all the work (TROJAN).
- When sending your files to another student or instructor, remind them to scan the files for viruses
- Scan all the software you download before putting on your computer.
I always run an anti-virus program, am I safe?
NO! You are certainly preventing a lot of harm, but keep in mind that new viruses are being continuously created. Therefore, there is a possibility you might get a virus that is unknown to the anti-virus program and the program won't be able to alert you. Many anti-virus programs do offer updates, which can be periodically downloaded so that your program is current.
What is the diagnosis for a viral infection?
This depends on the type of virus you got. There is a broad range of manifestation, some of them are actually neat, but don't let them fool you! Some viruses manifest themselves by dropping letters you type from the top of the screen to the bottom. Others display a diversity of colors on the screen. Still others make weird sounds on your computer. Others display messages on the screen. Be aware that viruses also might not manifest themselves at all until your turn off your computer and turn it back on just to realize your computer is not working at all.
What can computer viruses do?
There are many things viruses can do. Usually a virus is assigned to do single tasks, such as deleting non-system dependent files or programs (files used to run the programs you installed), deleting system files (files that your computer needs in order to function as a computer), renaming files, altering files, displaying graphics.
I see some weird things happening on my computer, is it too late?
NO! The best thing to do is to turn off your computer as soon as you detect something wrong. DON'T try to see what is happening! Then, get a bootable system disk that has a virus program and boot your computer with it. A system disk is a disk that carries all the core programs needed to start up the interaction between the hardware and the software of your computer. You can obtain such a disk from a local computer service.
After the anti-virus program is run, it should tell you what kind of virus was detected and if it was removed. If this doesn't happen, you should try another anti-virus program. After you get everything back to normal, get all your disks and virus scan them with the anti virus program. This will ensure you that your disks are not infected and that it is safe for you to use them. Announce to all of your friends and faculty that your computer detected a virus, and, if possible, give them the name of the detected virus.