A virus is a program – a piece of executable code – that has the possibly of cloning itself. Computer viruses can spread fast and they are hard to eradicate. They can be attached to any type of file and they are spread as files copied and sent from person to person. They can be contacted from a floppy disk or Cd, they can be launched when opening a program or accessing a file, any file, or they can be brought from the internet by downloading a file or accessing a web page and as attachments to e-mails.
Besides replication, some viruses have something else in common: their infecting routine. The behaviors of viruses vary from showing messages or images to destroying files, formatting the hard disk drive and other severe damage. If the virus does not inflict damage it can still cause problems by taking up space and memory, lowering the performances of the computer.
Nine rules for avoiding viruses would be:
1. Use an anti virus program at all times.
2. Install and keep active a firewall.
3. Make sure your system is up-to-date with all the existent updates.
4. Keep your browsers security settings at maximum.
5. Never click yes when your browser asks you if you want to install or open some content coming from an organization you don’t know or don’t trust.