Computer Viruses

1
Computer Viruses

• Made by Mészáros Fanni 9.

2
Virus Types

• E-mail viruses - moves around in e-mail
  messages
• Worms - is a small piece of software that uses
  computer networks and security holes to replicate
  itself
• Trojan horses -is simply a computer program

3
About the viruses

• called viruses because they share some of the
  traits of biological viruses
• made by people
• a computer virus must piggyback on top of some
  other program or document in order to get
  executed.

4
Origins

• people create viruses
• a person has to write the code, test it to make
  sure it spreads properly and then release the
  virus.
• a person also designs the virus's attack phase,
  whether it's a silly message or destruction of a
  hard disk.

5
Whats a worm?

• usually exploits some sort of security hole in a
  piece of software or the operating system.
• Examplethe Slammer works (which caused mayhem
  in January 2003) exploited a hole in Microsoft's
  SQL server.

6
ILOVEYOU Virus

• appeared on May 4, 2000
• contained a piece of code as an attachment
• people who double clicked on the attachment
  allowed the code to execute.

7
Executable Viruses

• spreading part is the infection phase of the virus

8
Code Red

• Using a network, a worm can expand from a single
  copy incredibly quickly. For example, the Code
  Red worm replicated itself over 250,000 times in
  approximately nine hours on July 19, 2001.

9
Viruses

• computer viruses are called viruses because they
  share some of the traits of biological viruses.
• passes from computer to computer like a
  biological virus passes from person to person.

10
Multipartite Virus

• A Multipartite Virus infects boot sectors and
  files. Often, an infected file is used to infect
  the boot sector thus, this is one case where a
  boot sector infector could spread across a
  network.