what is a computer virus

A computer virus is another type of malware that can replicate itself and spread from one computer to another. It attached itself to a legitimate program, executive piece of software, and then reproduces itself when that program is run. Viruses spread by reproducing and inserting themselves into programs, documents, or e-mail attachments. They can be transmitted through e-mail or downloaded files and they can be presented on DVDs, CD's, USB-drivers and any other sort of digital media.



Before a virus can infect a victim computer it requires an action, for example, the malicious program inside e-mail attachments usually only strike if you open them. The effect of virus can cause the complete destruction of computer programs and data.

Some viruses can infect files without increasing their sizes or damaging the files. They accomplish this by overwriting unused areas of executable files. These are called cavity viruses. Some viruses try to avoid detection by killing the tasks associated with anti-virus software before it can detect them.

Some viruses rewrite themselves completely each time they are to infect new executables, to avoid being detected by emulation. Viruses that uses this types of method are said to be metamorphic.

How to prevent virus

• To prevent yourself against viruses, you should always keep your anti-virus up-to-date and your operating system and application patched.
• Install anti-virus software that detects and removes infections as they appear.
• Pay attention to the instructions while downloading files or any programs from the internet.
• Avoid opening the attachments received from an unknown sender as viruses spread via e-mail attachments.