Facts and Myths about Computer Viruses
—Technology Training Center—

When dealing with computer viruses, it’s important to remember that they are software. That means:

  • Viruses can do anything other software can do:
  • Viruses can delete files.
  • Viruses can format hard drives or scramble the data on them.
  • Viruses could (in theory) communicate over a network.
  • Viruses cannot do anything impossible for other software
  • Viruses cannot damage your CPU.
  • Viruses cannot physically destroy your hard disk, although they can scramble the data on them.
  • Viruses cannot destroy your computer’s RAM.
  • Viruses cannot cause your computer system to explode.

People intentionally write computer viruses, they do not appear spontaneously. They are not accidental mutations of “normal” software.

Distinguishing Features of Different Types of Malicious Software

Features

Viruses

Trojan Horses

Tapeworms

Reproduction

Viruses reproduce by modifying or replacing other software. The “infected” (or “host”) software then acts as a “vector”, infecting other software.

Trojan Horses do not reproduce.

Tapeworms reproduce on their own by making copies of themselves.

Transportation

“Infected” software is transported to another computer, usually by disk or downloading, where the infection process starts again.

Computer users are duped into installing Trojan Horses by claims that they do something good.

“Network worms” find their own way to other computers over a network. Other worms spread via “infected” disks.

Dependencies

Viruses function by “infecting” other software. They are essentially code fragments.

Trojan Horses are self-contained programs.

Tapeworms are self-contained programs, or systems of programs.

More info: http://training.binghamton.edu