The document discusses different types of malware that can infect computer systems, including viruses, worms, Trojan horses, spyware, adware, and ransomware. It provides examples of how each type can negatively impact computers. Malware may enter systems through sharing files, visiting malicious websites, downloading files without caution, or installing software without reading agreements. Once inside, malware can slow systems down, use memory and disk space, steal information by capturing keystrokes, or block access to systems until a ransom is paid. The document also outlines specific types of computer viruses like macro viruses, boot sector viruses, memory resident viruses, and file infector viruses.

1. Computer Virus

2. Malware
 Malware is used to describe any malicious program on a computer or mobile device
installed without the consent of the user and can cause a number of annoying effect such
as hard disk has more files; computer tends to run slower; computer start rebooting;
application takes time to load; computer hangs and restart its own.
 A malware may enter your computer system through the Internet or through an infected
pen drive, a DVD, a CD. For examle
 Sharing files- photos, audio or video
 Visiting malicious website
 Downloading free games, media players and other system utilities.
 Installing software without reading license agreements.

3. Computer Virus
 Malware is used to describe any malicious program
on a computer or mobile device installed without the
consent of the user and can cause a number of
annoying effect such as hard disk has more files;
computer tends to run slower; computer start
rebooting; application takes time to load; computer
hangs and restart its own.
 A malware may enter your computer system through
the Internet or through an infected pen drive, a DVD,
a CD. For examle
 Sharing files- photos, audio or video
 Visiting malicious website
 Downloading free games, media players and other
system utilities.
 Installing software without reading license
agreements.

4. Worms
 It is a program that replicates
and spreads itself to another
computer system with the help of
computer network.
 It does not target or infect
specific files already present on a
computer instead eat up the
memory on the disk space.

5. Trojan Horse
 It is a malicious program that
appear useful but in reality,
damages the files.
 It capture and store all keyboard
activity and mouse clicks.
 In this manner a Trojan easily
steals confidential information
such as account login and
password.

6. Spyware
 Spyware is sent to someone’s
computer intentionally to report
on the activities and preferences
of the computer’s user or
disclose information about the
data stored on computer.
 Examples :- Look2me, Zango

7. Adware
 It is an advertising-supported
software that generates revenue
for its developer by automatically
generating online advertisement
such as pop up ads.

8. Ransomware
 It is a type of malcious software
that threatens to publish the
victim’s data or limits user from
accessing their system and block
access to it unless a ransom is
paid.
 If you refuse to pay the data is
deleted.

9. Types of Computer Virus
 Macro virus infect certain types of data
files. Most macro viruses infect Microsoft
Office files.
 Examples. Relax, Melissa. A.
Macro Virus Boot Sector Virus
 Boot sector virus infect the boot record
on hard disks and also on CD’s and
DVD’s.
 A boot sector does not need to be able to
successfully boot the victim’s computer to
infect it.
 The boot sector virus stays in memory
and infects other storage medic such as
hard disk or any type of bootable media.
 Examples. Brain Virus, disk killer.

10. Memory
Resident Virus
 These viruses act when the
operating system starts running,
after which any open files can
get infected.
 Example . Randex, CMJ
 File infector viruses infect files
which contain executable code
such as .EXE .COM Files.
 This virus will stay in memory
and continue to infect other
programs or files when they
are executed.
File Infector
Virus Multipartite Virus
 The boot sector virus stays
in memory and infects
other storage medic such
as hard disk or any type of
bootable media.
 File infector viruses infect
files which contain
executable code such as
.EXE .COM Files.

11. Questions?