1. MOST RECENT ATTACKS BY
VIRUS,
WORMS & TROJANS

2. INDEX
 VIRUS
• What Is Computer Virus?
• History Of Computer Virus.
• Background
• Virus Through The Internet.
• Symptoms Of Virus Attack.
• Typical Things That Computer
• Viruses Do.
• Prevention of Virus.
 WORMS
• What Is Worms?
• History Of Worms.
• Anatomy of Worms.
• Types Of Worms.
• Harmful Effects Of Worms.
• Prevention of Worms
 TROJANS
• What Are Trojans?
• Types Of Trojans.
• What Trojans Can Do.
• Detection Of Trojans.
• Prevention of Trojans
 COUNTER-MEASURE OF TROJAN,VIRUS,WORMS
 DIFFERENCE BETWEEN VIRUS,WORMS & TROJANS

3. VIRUS
 A computer virus is a computer program that can copy
itself and infect a computer.
 The term "virus" is also commonly used to refer to other
types of malware, adware and spyware.
 Viruses can increase their chances of spreading to other
computers by infecting files on a network file system or
a file system that is accessed by another computer.
 Once it’s running, it spreads by inserting copies of itself
into other executable code or documents

4. THE HISTORY OF COMPUTER VIRUSES
• 1981 Apple Viruses 1, 2, & 3
• 1980’s Fred Cohen
• 1987 Lehigh Virus
• 1988 The first anti virus software
• 1990 The first polymorphic viruses
• 1991 Symantec releases Norton Anti Virus
• 1992 The Michelangelo Virus
• 1994 Kaos4 virus spreads via adult websites.
• 1996 The Concept virus

5. • 1999 The Melissa Virus
• 2000 The I Love You Virus
• 2001 The Code Red Worm
• 2003 The Slammer Worm.
• 2004 MyDoom

6. BACKGROUND
 There are estimated 30,000 computer viruses in existence
 Over 300 new ones are created each month
 First virus was created to show loopholes in software
Virus through the Internet
 Today almost 87% of all viruses are spread through
the internet (source: ZDNet)
 Transmission time to a new host is relatively
low, on the order of hours to days
 “Latent virus”

7. SYMPTOMS OF VIRUS ATTACK
 Computer runs slower then usual
 Computer no longer boots up
 Screen sometimes flicker
 PC speaker beeps periodically
 System crashes for no reason
 Files/directories sometimes disappear
 Denial of Service (DOS)

8. TYPICAL THINGS THAT SOME CURRENT
PERSONAL COMPUTER (PC) VIRUSES DO
 Display a message.
 Erase files
 Scramble data on a hard disk
 Cause erratic screen behavior
 Halt the PC
 Many viruses do nothing obvious at all except spread!

9. PREVENTION OF VIRUS
• Most antivirus are capable of detecting and removal of
major virus.
• Get the latest Anti-Virus Software.
• As prevention is concern use of any detection tool is
preferred e.g. adware, spyware.
• Not to open any unknown source downloads. To prevent
attacks.
• Even after using these precautions, if the virus creeps
into your system, it can be detected in various ways
apart from using a virus scanner for it.
• Always keep backup of your data/programs
• Keep floppies Write-protected (especially if they are
bootable.)

10. WORMS
 The actual term "worm"' was first used in John Brunner’s
1975 novel, The Shockwave Rider.
 A computer worm is a self-replicating malware
computer program, which uses a computer network to
send copies of itself to other nodes and it may do so
without any user intervention.
 Unlike a computer virus, it does not need to attach itself
to an existing program. Worms almost always cause at
least some harm to the network, even if only by
consuming bandwidth, whereas viruses almost always
corrupt or modify files on a targeted computer.

11. HISTORY OF WORMS
 The first worm to attract wide attention, the
Morris worm, was written by Robert Tappan
Morris, who at the time was a graduate student at
Cornell University.
 It was released on November 2, 1988
 Morris himself was convicted under the US
Computer Crime and Abuse Act and received
three years probation, community service and a
fine in excess of $10,000.

12. ANATOMY OF WORMS
 Attack Mechanism
 Payload
 New target selection

13. TYPES OF WORMS
 Conficker Worm
 Email and Instant Message Worms
 Internet Worms (Morris Worm)
 IRC Worms
 File-Sharing Network Worms
 Slapper Worm

14. HARMFUL EFFECTS OF WORMS
 A worm uses a compromised system to spread through
email, file sharing networks, instant messenger, online
chats and unprotected network shares.
 Infects files, corrupts installed applications and damages
the entire system.
 Steals or discloses sensitive personal
information, Valuable documents, passwords, etc.
 The worm installs a backdoor or drops other dangerous
parasite.
 Connection speed & System performance.

15. TROJANS
 A Trojan horse or Trojan, is a destructive program that
masquerades as an application.
 The Trojan Horse, at first glance will appear to be useful
software but will actually do damage once installed or
run on your computer.
 Trojans are also known to create a backdoor on your
computer that gives malicious users access to your
system.
 Unlike viruses and worms, Trojans do not reproduce by
infecting other files nor do they self-replicate.
 Some well known Trojans:Net-bus,Girl friend, Back
orrifice ,Flooder, Vundo Trojan etc.

16. PREVENTION OF WORMS
• A personal firewall should be run on any system that
is not behind a corporate firewall. This should be done
on any computer that connects to the internet.
•Patching your system with updates to fix the
vulnerabilities.
•Patching is the act of downloading updates to the
vulnerable operating system or application and
applying the update to the program.
•sometimes the worm can infect the system before the
anti-virus software can detect it.

17. TYPES OF TROJANS
1) Remote access Trojans
2) Password sending Trojans
3) Keyloggers
4) Destructive
5) Denial of service(DOS) Attack Trojans
6) Mail-Bomb Trojans
7) Proxy-Wingate Trojans
8) FTP Trojans
9) Software Detection Trojans

18. WHAT TROJANS CAN DO?
 Use of the machine as part of a Botnet (e.g. to
perform automated spamming or to distribute
Denial-of-service.)
 Uninstallation of software, including third-party
router drivers.
 Downloading or uploading of files on the
network hdd.
 Watching the user’s screen.
 Spreading other malware? Such as viruses. In
this case? The Trojan horse is called a dropper or
vector.

19. WHAT TROJANS CAN DO?
 Modification or deletion of files.
 Data theft(e.g. retrieving username or postal
code information)
 Erasing or overwriting data on a computer.
 Encrypting files in a crypto viral extortion
attack.
 Crashing the computer.
 Corrupting files in a subtle way.
 Setting up networks of zombie computers in
order to launch Dodos attacks or send spam.

20. WHAT TROJANS CAN DO?
 Spying on the user of a computer and covertly
reporting data like browsing habits to other
people.
 Logging keystrokes to stealing formation such as
passwords and credit card numbers (also known
as a key logger)
 Phish for bank or other account details? Which
can be used for criminal activities.
 Installing a backdoor on a computer system

21. DETECTION OF TROJANS
a) Suspicious open ports:
b) Monitoring outgoing traffic:
c) Detection tools:
d) Start up files:

22. PREVENTION OF TROJAN
• One of most important difference between
Trojan and his friends is that it does not
replicate.
• Thus limit the destruction.
• Anti-virus can detect and safely deleted
the Trojan.

23. COUNTER-MEASURE OF
TROJAN,VIRUS,WORMS
•Virus
-Virus detection/disinfection software
•Trojan
-Sandboxing
- Code reviews
•Worms
-Sandboxing
-Quick patching: fix holes, stop worm

24. DIFFERENCE BETWEEN VIRUS,WORMS &
TROJANS
VIRUS WORMS TROJAN
A computer A computer
Definition WORM is a self-
S
virus attaches A Trojan, is
itself it contained
program (or set software that
travels to a
of programs), appears to
program or that is able to perform a
file spread desirable
enabling it to functional copies function for
spread from of itself or its the user prior
one computer segments to
to run or
to another, other computer
systems (usually
install, but
leaving steals
infections via network
connections). information or
harms the
system

25. VIRUS WORMS TROJANS
TYPES 1.Trojan Horse 1.Remote
2.Worm 1. “host Access
3.Macro computer Trojans
worms” & 2.Data
Sending
2.”network
Trojans
worms”.
3.Destructive
Trojans
4.Proxy
Trojans
5.FTP
Trojans
6.security
software
disabler
Trojans
7.DoS
Trojans

26. VIRUS WORMS TROJANS
What they virus may exist the worm cause serious
on your consumes too damage by
do? computer but it much system deleting files and
actually cannot memory (or destroying
infect your network information on
computer unless bandwidth), your system.
you run or open causing Web
the malicious servers,
program network servers
and individual
computers to
stop responding
EXISTENCE NOT NOT INDEPENDENT
INDEPENDENT INDEPENDENT

27. VIRUS WORMS TROJANS
SELF- . A virus attaches a worm is self- Unlike virus and
REPLICATION itself to, and contained and worms
becomes part of, does not need to Trojans do not
another be part of reproduce by
executable another program infecting other
program to propagate files nor do they
itself. self-replicate.

28. VIRUS WORMS TROJANS
Propagation
virus does not Worms . Trojans are
have a propagate and also known to
propagation infect other create a
vector. i.e., it computers. backdoor on
will only effect your computer
one host and that gives
does not malicious users
propagate to access to your
other hosts. system,
possibly
allowing
confidential or
personal
information to
be
compromised

29. VIRUS WORMS TROJAN
EXAMPLE Melissa Nimda, S
S Code Red I Love You

30. BIBLIOGRAPHY
•Virus-
http:// en.wikipedia.org/wiki/Computer_virus
•Trojan
http:// en.wikipedia.org/wiki/Trojan_horse
•Worm-
http://en.wikipedia.org/wiki/Computer_worm
Trojan Horses -
http://www.mpsmits.com/highlights/trojan_horses.sh
tml