Harmful software

1. HARMFUL SOFTWARE
Malware and Virus

2. Software and Computer
 Software is an inseparable component of the computer
 Different types of software have made our work easy
BUT…
Some software that are very harmful for our system and data

3. Malware
 Combination of two words
Malicious + Software
Software written and developed to create mischief or hurt the user
Various types:
 Virus
 Trojan Horse
 Worms
 Rootkits
 Backdoors
 Ransomware
 Spyware
 Adware
 Sacreware

4. Purpose of Malware
 In the beginning Malware was written for purpose of
experiments.
 Sometimes, it was also written as a joke.
 With advancement in technology, it is being used with
more intensions:
 Steal Personal informations
 Obtain bank account details and credit card details.
 Disturb activities
 Take control of users computer for illegal activities
 Send email spams
 Advertise products

5. Symptoms of presence of Malware
 Unexplained messages start appearing on the screen
 Some files deleted on their own.
 Keyboard does not work properly
 Unexplained problems occur while printing files
 Making system unusable/ crashing of the system
 Slowing down of your system
 Automatic rebooting/restarting
 Data on the system becomes inaccessible
 Random playing of strange sounds

6. Types of Malware
1. Virus
 The term ‘VIRUS’ was first used by John Von Neumann in 1949
 A computer virus is nothing but an electronic version of ‘Biological virus’
Vital
Information
Resource
Under
Siege
 When enters the computer, it replicates itself and cause infection.
CREEPER is widely acclaimed as
the first virus on ARPANET
(First version of Internet)

7. Types of Viruses
 File Infector Virus: This virus attacks executable files of the computer.
 This virus either deletes or damages files.
 Eg: Sunday, Invader, Cascade
 Boot Sector Virus: Infects the boot sector of hard disk
 Either copies boot sector instructions present in hard disk to some other
location or overwrites these instructions
 Eg: Disk Killer, stone Virus
 Macro Virus: Infects the macro files of MS Office files
 Difficult to detect(They enter the system as a part of office file and appear
non-suspesious)
 Eg: Nuclear, DMV

8. 2. Trojan Horses
 These are ordinary looking files but are actually programs
that delete/ corrupt files.
 They are transferred as innocent attachments to an email.
 They do not replicate themselves.
 They are usually written with the intention of stealing
data.
 These are used to take unauthorized access and control of
infected system.
 Eg: PC-Write (First Trojan Horse in cyber history)

9. The Trojan Horse can:
 Crash the computer
 Corrupt user data
 Format HD
 Make unauthorized transfer of data/electronic money
 Modify/delete data
 Unnecessary download or upload files
 Control computer remotely

10. 3. Worms
 Viruses are transferred from one system to another as an
attachment to a file or a program.
 Worms can spread on their own. (Do not need the support
of another file)
 Worms are designed only to spread from one computer to
another.
 NOT TO CAUSE CHANGES IN DATA OF THE SYSTEMS.
 Some worms cause problem of increased network traffic.
 Eg: Red Code, Slammer worm, Storm

11. 4. Backdoors
 When you log into a computer system, it asks for the user
name and password
 Backdoor malware has been designed to bypass this
process
 It can get installed to a computer with/without the
knowledge of the user.
 Eg: Subseven, NetBus, Award BIOS

12. 5.Rootkit
 Rootkit is a special type of malware that gives
administrative rights to use the computer.
 Unlike other malware, they are not harmful.
 They are simply cover other malware, gain entry to the
computer and then attack the computer using other
malware like virus, Trojan etc.
 Eg: Back Orifice

13. 6.Spyware
 Spyware is a type of malware that does not
corrupt the computer
 It is designed to collect personal information
about an individual/ organization.
 It is designed to collect informations like web
visiting history of the user
 advertisement start appearing according to
the web visiting history
 Some spyware designed to download unwanted
softwares/files form internet.
 It does not multiply

14. Symptoms of spyware infected systems:
 Performance of the computer has started
decreasing.
 The free space in the computer HD has
decreased on its own.
 Huge network traffic
 Applications installed on the computer
started closing in their own.
 User has started facing difficulty in
connecting to the computer.

15. Check your knowledge:
 Macros present in ……………………….. File.
 Ans: Office file
 Malware is written and developed to
create…………… or ………………….. The user.
 Ans: Mischief or Hurt
 ………………… collects information about an
individual or an organization.
 Ans:Spyware
 ………………………. Is considered as the first Trojan
Horse in cyber history
 Ans:PC-write
 …………………….. Is widely acclaimed as the first
virus on ARPANET
 Creeper