Intruders Classification of ID system Malicious software Types of virus Firewalls Characteristics of firewalls Firewalls responsibilities

1. NETWORK SECURITY
NAME OF THE STAFF : Mrs. M. FLORANCE
DYANA
NAME OF THE STUDENT : S.MAREESWARI,
J.GAYATHRI DEVI,
R.KAVITHA.
REGISTER NUMBER : CB17S 250393
CB17S 250370
CB17S 250383
SUBJECT CODE : P8MCA27
CLASS : III BCA-A
BATCH : 2017-2020
YEAR : 2019-2020

3.  Introduction
 Intruders
 Classification of ID system
 Malicious software
 Types of virus
 Firewalls
 Characteristics of firewalls
 Firewalls responsibilities

4. Introduction
 The security mechanism of the system are designed so as to praventum
authorized access to system resources and data.
 Intrusion detection (ID) is type of security management system for
computers and networks.
 ID gathers and analyse information from various areas with in
computer or a network to identify possible security breaches which
include both intrusion and misuse.
 ID uses vulnerability assessment (scanning), that is software
technology developed for assess the security of computer system or
network.

5. INTRUDERS
 Intruder is a person who enters in territory that does not
belongs to him
Types:
 Masquerader
Not authorized to use computer, penetrates system protection
by the way of legitimate user account.
 Misfeasor
A legitimate user who can access assets that he is not
authorized to.
 Clandestine user
A user who gains supervisory access to the system, can be
either inside or outside.

6.  Unauthorized access is an attempt for
 Accessing information.
 Manipulation of information.
 Render a system unreliable or unusable.
 Need for Intrusion Detection System
 To prevent problem behaviours.
 To detect attack and other security violation.
 To detect and deal with preambles of attack.
 To document the existing threats.
 quality control for security design and administration.
 To provide useful information about intrusion that is to take place, allowing
improved diagnosis , recovery and corrections.

7. Intrution detection
 Monitoring and analysing both user and
system activities.
 analysing system configurations and
vulnerabilite.
 Assessing system and file security.
 Ability to recognize patterns of attacks.
 Analysis of abnormal activity patterns.
 Tracking user policy violation.

8. Classification of ID system
 Attempted break-ins : which are detected by
atypical behaviour profiles or violation of
security constraints.
 Masquerade Attacks: which are detected by
atypical behaviour profiles.
 Penetration of security control system, which is
detected by monitoring for specific patterns of
activity.
 Leakage, which is detected by atypical use of
system resources.
 Denial of Service, which is detected by atypical
use of system resources Malicious.

9. Malicious software
 Is referred as Malware
 It includes computer viruses, worms,
Trojans, spywares, and other programs
written specially to spy network traffic,
 record private communications , executes
unauthorized commands,
 steal and distribute private and confidential
information , disable computers , erase files
etc.

10. Types of viruses
 Parasitic viruses:
 Virus that attached self to file in order to propagation
Boot Sector Virus.
 Polymorphic virus .
 A virus that changes its characteristics with each
infections and makes detection more difficult.
 Virus that hides it stracks after in facting computer.

11.  Macro virus
 Hybrids
 Email Viruses
 Types of Worms
 Email Worms
 Spreading goes through infected email messages
 Instant messaging worms
 Spreads via instant messaging applications by
sending links to infected websites

12.  Internet worms
 Will scan available network resources using
local network or operating system service
 IRC worms
 Chat channels are the main target of this kind
of worm
 File worms sharing and network
 Worm copies itself into shared folder

13.  Trojan Horses
 Contains hidden code that, when invoked
performs some unwanted function
 Only author of trojan horse program can have an
access to source code of useful programs that is
attractive to other users and then add code so that
the program performs some harmful function in
addition to its useful function.
 Spyware
 Is a programming that is put in someone’s
computer to secretly gather information about the
user and rely it to advertiser other
interestedparties

14. FIREWALL
Introduction
 Is a system designed to prevent unauthorized access to or from private
network.
 It can be effective means of protecting local system or network of systems
from unauthorized network users, at the same time affording access to the
outside world via WAN and internet.
 Firewalls is the one of the first line defense in a network.
 They can be implemented both in hardware and software
 Firewall are most often configured to be transparent to internal network
user and non transparent to outside network users.
 They are often installed between network of entire organization and
internet, but could also be installed in an internet to protect individuals
document.

15. Characteristics of firewalls
 All traffic between two network must pass
through firewall
 Only traffic that is authorized by local security
policy is permitted to pass
 The firewall itself is immune to penetration
 A firewall cannot guarantee protection from
outside attack Firewall implementation
requires risk analysis to define the level of
protection
 Firewall policy is a competent of local policy

16. Firewalls responsibilities
 Block unwanted traffic
 Direct incoming traffic to more trustworthy internal system
 Hide vulnerable internal network system
 Hide internal network information such as system names, network
topology, network device types, internal user id’s etc
 Provide more robust user authentication
 Benefits
 Increased ability to enforce network security standards/
policies
 Centralization of inter network audit capability

17. Limitation of firewalls
 Firewall does not provide data integrity
 Firewall do not check traffic not sent through them
 Firewall protect nothing if they have been
compromised
 Firewall authenticate data packets at the transport
and network layer.
 Firewall provides limited confidentiality
 Firewall do not protect against insider threats
 Encrypted traffic cannot ne examined and filtered