Glossary of Antivirus Terms


  • Displays advertising banners on web browsers
  • Not always threatening
  • Creates pop-ups
  • Can cause sluggish network connectivity


  • Undesirable but less troublesome than malware
  • Includes some spyware, adware and joke programs.


  • Malicious Software
  • Infiltrates or damages a computer system without the owner’s knowledge or consent
  • Includes computer viruses, rootkits, spyware, and trojan horses


  • Designed to take full control of a machine’s operating system
  • Commonly encrypts files and demands payment to decrypt

Safe Mode

  • Diagnostic mode for a computer operating system
  • Reduces operating system functionality to a minimum
  • Makes problem isolation much easier


  • Installs without the user’s knowledge
  • Takes partial control of a machine
  • Records personal information, such as surfing habits
  • Actively redirects web browsers
  • Secretly installs third party software

Trojan Horse

  • Appears to be a legitimate,  desirable program
  • Actually performs undisclosed malicious functions
  • Most computer worms are trojan horses to hide the fact that access has been opened to intruders.


  • Can copy itself and secretly infect a computer
  • Can damage files
  • Can open connections allowing others to control the machine


  • Sends copies of itself to other machines on a network, often without user intervention.
  • May only cause lowered bandwith as it spreads on the network
  • Most commonly installs a back door to give someone access