EducationalITGS HL

What is Malicious Software? (for beginners)

What are viruses/worms/trojan horses/drive by downloads and all other malware? This is a brief guide for noobs/beginners.


  • ›A harmful program designed to cause damage to a computer system
  • ›Replicates itself
  • ›Hides self
  • ›Attaches to files


  • ›Virus that automatically spreads without user interaction
  • ›Opening infected email
  • ›Plugging flash drive

Trojan Horses

  • ››A virus that tricks user into opening it
  • ›Disguise self as a useful program


  • ›Malware that monitors and spies on the user
  • ›Keylogger
    • ›Passwords
    • ›Sensitive Data
    • ›Takes pictures


  • ›Virus that is very hard to remove
    • ›Hides itself
    • ›Modifies operating system
  • ››Sometimes impossible to remove
    • ›Need to reinstall windows

Impacts of malicious software

  • ›Less destructive
    • ›Display annoying messages
  • ›Destructive
    • ›Data Destruction
    • ›Break Operating System
    • ›Steal Data/Passwords etc.

Drive-by downloads

  • ›Automatically downloaded malware
    • ›User doesn’t realize
  • ›Ex: Pop-ups (pop ups usually contain viruses)

DDOS – Denial of Service Attacks

  • ›Multiple computers attacking a system at one time
  • ›Causes targeted system to crash
  • ›Attackers = Virus infected computers

How to Avoid Malicious Software?

  • ›Install anti-virus
    • ›Update everyday
  • ›Only download from safe websites
  • ›Never open any attachment/link that you are not expecting



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