How to Prevent Your Computer from Virus Attack.

Virus can be defined as a deviant program written by computer programmers that attaches itself to a computer system and attacks or corrupt data or programs. A virus makes the computer malfunction. Worms are example of virus that copies itself repeatedly into the memory or onto a disk drive. It swells itself up in the memory until no space is left. This affects the operation of the computer system.
Virus is of different types and they are:-
a. Executable file virus. File virus attaches itself to program files or executable files, those that actually begins a program. In DOS, these files have the extensions . com and .exe. when a program is run, the virus starts working, trying to get into the main memory andd infecting other files.
b. Trojan horse. They place illegal, destructive ntructions in the middle of legitimate programs, such as computer games. Once you run the program, the trojan horse starts doing its damage when you are not aware.
c. Multipartite virus. These are virus that affect both the boot sector and the executable files.
d. Document virus. These are viruses that attack the doents that users have created or are trying to access. At times, these virus change the font styes of documents and make them show jargons. Other types of viruses affect the miniature programs known as macros and soon.
The following are examples of viruses and worms :-
i. Klez worm, Ron+ Ok-br worm,AntCmos, Antiexe, Form A,NYB are examples of boot sector viruses that multiples themselves on the disk until no space is left.
ii. Logic bomb. These are viruses that affect computer systems on certain date and time e.g. April 1st and christmas virus. These viruses are very harmful to computers on the said date and time.
iii. Viralert virus. Is an example of executable file viruses. Alama virus and sleeper virus are example of viruses. Trojan horse is also another example of viruses.
Virus just doesn't appear in the computer but comes through a source. The sources of computer viruses are :-
1. Hardware components. Some hardware components such as the removable storage device like diskettes, flash disk, zip disk, CDS, hard disks and when copying through networks, help to transmit viruses very fast. This can be as a result of transmitting data from one computer system, which may contain virus. Some of the hardware, which have programs that make them work, may have virus programs embedded in them which may be made active after some time of usage.
2. Software. Software or programs that are written by professionals may also contain viruses. The intention of this may be to check piracy. Piracy is an unauthorized copying of software. You copy a software from one diskette to another. Viruses embedded in the software may be active after some time of usage to destroy software so that new ones may be purchased.
3. Through internet. Viruses might infect our system s when they are exposed to the internet. Our systems on the internet are prone to being infected with viruses. Viruses are not contained in the mails we send but are contained in programs we downloading files on the internet.
How do you know if a sytem is virused? Every virus has symptoms and these are the symptoms;-
1. Viruses slow down system's time. Wen a user issues instructions to the computer, it takes time to receive response.
2. Presence of tiny dots. These dots make it difficult for one the system effectively.
3. Wandering across the screen. When the virus attacks the VDU's VGA , it darts on wanders around the screen. The screen will not be stable.
4. Frequent shutting down of the computer system. This is as a result of boot – sector virus.
5. Incomplete saving of a file. When one is saving a file, it does not save completely because of the effect of the virus.
6. Viruses destiny the characters of any saved document making it difficult to boot normally. The operating system may also not be loaded properly.
7. There will be frequent appearance of storage characters on the screen of the computer system.
You can protect your system against virus infection by doing any of the following:-
1. Purchase original copies of anti – virus software for your system. These anti – virus software should be updated at regular intervals because they are always designed for a specific period of time.
2. Avoid the use of foreign storage devices e.g. zip disks, flash disks, diskettes to mention a few that may contain viruses. You should check them with anti- virus software before use, if necessary.
3. When you are accepting software or script on internet sites or reading mail from unknown senders, it is best not to run a program from that site without checking it with antivirus program.
4. Always purchase original copies of software that may interest you.
5. Obtain an anti – virus program. Most reputable companies that create virus protection programs release an evaluation copy that an internet user can download for free and use for certain time. It can check your computer for viruses and repair damaged or deleted files that are infected with viruses.
6. System inoculation. You should be checking your system for deleting viruses regularly.
Alternatively, you could buy and install a firewall which blocks entrance of viruses into your system.