Computer Viruses

In general terms a virus is a program that runs on a system against the owner's or user's wishes and knowledge. A virus is a program that reproduces its own code by attaching itself to other executable files in such a way that the virus code is executed when the infected executable file is executed. Viruses have one or more methods they use to spread. Most commonly they will attach a file to an e-mail message and attempt to trick victims into running the attachment. The First Virus was found in 1981. By number, there are well over 100,000 known computer viruses.

How Viruses or Worms Spread
Most commonly viruses today use e-mail to spread however they have used one or more of the following methods to spread in the past.
• Some viruses will load themselves onto any part of a writable removable drive as possible and spread from computer to computer as people use the removable drive.
• Most viruses will spread themselves using e-mail attachments.
• Most viruses do their "job" by placing self-replicating code in other programs
Symptoms of Computer virus on our pc.
• Alter the way of working.
• File size is changed or miss located.
• Speed of Computer is too slow even May Hang while working on pc
• May display unnecessary message.
• Computer Hardware may not response.