Submitted By:- Nitesh Kumar Yadav Submitted To:- Subash Paudel SirClass :- 10 ‘B Computer DepartmentRoll no:- 3 Laboratory Higher Secondary School Kirtipur

Project Work of Computer

PRESENTATION ON:COMPUTER NETWORK AND INTERNET.Introduction:A computer network is simply two or more computers connected together so they exchange information. A small network can be as simple as two computers linked together by a single cable or it may be a group of several computers connected at a central networking device through wired or wireless medium.Computer Network Components:Server: Powerful components that provides services such as print service, file service, web service etc. to the other computers on the network.Client: Computer that uses the services that a server provides. The client is less powerful than server.Media: A physical connection between the devices on a network. The media may be wired or wireless.Network Adaptor: Network adaptor or network interface card (NIC) is a circuit board with the components necessary for sending and receiving data. It is plugged into one of the available slots on the PC and transmission cable is attached to the connector of the NIC.Resources: Anything available to a client on the network is considered as resource. User: Any person that uses a client to access resources on the network is user.

Advantages of Computer Network: Network allows data transmission among far areas also within local areas. Network allows users to share common set of data files and software stored in a

main system. Network allows users to share common hardware resources such as printers, fax

machines, modem, etc. The cost of computing is reduced to each user as compared to the development

and maintain of each single computer system. Disadvantages of Computer Network: If the network stops operating then it may not be possible to access various

hardware and software resources. The efficiency of a network is very dependent on the skill of the system manager.

Badly managed network may operate less efficiently than stand alone machines. It is difficult to make system secured from hackers, novices or industrial espionage. As traffic increases on the network, the performance degrades unless it is properly

designed.

Client server Network1) A central server is available to all

users.2) Users IDs, passwords, and access

levels are controlled by the central computer.

3) Backup facilities are centralized: data and information held centrally are backed up regularly.

4) All users are reliant on the service provided by the server. If the central computer goes down, all the users affected.

Peer-to-peer Network1) Sharing facilities are distributed

throughout the network.2) Security is not centrally

controlled.3) Backup is the responsibility of

individual computer users.4) No reliance on a central

computers.

Types Of Networks.1) LAN (Local area network): Owned by a single organization. Diameter of not more than three kilometers.2) WAN (Wide area network): Owned by multiple organizations. Covers a large geographical area.3) MAN (Metropolitan area Network): Based on the network architecture, the transmission speed can be

higher for short distances. A MAN, which can include one or more LANs as well as

telecommunications equipment such as microwave and satellite relay stations, is smaller than a wide area network but generally operates at higher speed.

Network TopologiesA network topology refers to the physical layout of the network in which all the devices are connected. This includes all the hardware that makes up the network.Bus Topology: Bus topology uses a common backbone to connect all the network devices in a network in a linear shape. A single cable called a bus with a terminator at each end functions as the shared the shared communication medium for all the devices attached with this cable with an interface connector.• Advantage: 1> Easy to connect a computer or peripheral to a linear bus. 2> Requires

less cable length than a star topology.• Disadvantage: 1> Whole network shuts down if there is a break in the main cable. 2>

Terminators are necessary at both ends of the backbone cable.Ring Topology: A ring topology is a network topology or circuit arrangement in which each network device is attached along the same single path to other devices, forming a path in the shape of a ring.• Advantage: 1> Performs better than a star topology under heavy network load. 2> Can

create much larger network using Token Ring.• Disadvantage: 1> Moves, adds and changes of devices can affect the network. 2>

Much slower than an Ethernet network under normal load.

Star Topology: In the computer networking world the most commonly used topology in LAN is the star topology. All the computers in the star topologies are connected to central devices like hub, switch or router.• Advantage: 1> Easy to install and wire. 2> Easy to detect faults and to

remove parts.• Disadvantage: 1> Requires more cable length than a bus topology. 2>

If the hub or concentrator fails, nodes attached are disabled. Network ProtocolA protocol is a set of rules that governs the communications between computers on a network. Standard networking Protocols Transmission control protocol/Internet protocol (TCP/IP) File transfer protocol (FTP) Hypertext transfer protocol (HTTP) Simple Mail transfer protocol (SMTP) Post office protocol (POP)

Transmission MediumIt is a medium through which information usually moves from one network device to another. Guided Transmission Media: It uses a cabling system that guides the data signals along a specific path.• Twisted Pair Cable: 1> Unshielded twisted pair 2> Shielded twisted pair.• Fiber Optic Cable• Co-axial CableCable connectors:• Twisted pair cable: RJ-45• Co-axial cable: BNC• Fiber optics cable: ST connectorUnguided Transmission Media: It is a technology that provides the ability to communicate between two or more entities over distance without the use of wires or cables of any sorts.• Infrared Rays• X-rays• Bluetooth• Ultra-violet Rays

Networking Hardware1) File servers: A file server stands at the heart of most networks. It is a very fast computer with a large

amount of RAM and storage space, along with a fast network interface card.2) Workstations: All of the user computers are connected to a network are called workstations. A typical

workstation is a computer that is configured with a network interface card, networking software, and the appropriate cables.

3) Network Interface Card: The network interface card (NIC) provides the physical connection between the network and the computer workstation.

4) Hub: A hub is typically the least expensive, least intelligent, and least complicated central device than switch and router. Actually it broadcasts the signals to the entire connected devices as it doesn’t know the exact destination.

5) Switch: A switch is a device that channels incoming data from any of the multiple ports to the specific output port that will take the data towards its intended destination.

6) Routers: A router translates information from one network to another. Routers select the best path to route a message, based on the destination address and origin.

7) Bridges: A bridge is a device that allows you to segment a large network into two smaller, more efficient networks.

8) Gateways: A gateway is a network node that allows you to gain entrance into a network and vice versa.

9) Modem(Modulator-demodulator): Modem is a hardware that directly converts digital signal from a computer or other digital devices into analog form for transmission over analog link (telephone line) and vice-versa.

InternetIntroduction: The internet is a global collection of high powered computers that are connected to each other with network cables, internet lines, microwave dishes, satellites etc. Internet is the largest computer network that connects millions of computers around the world. It connects several thousand computer networks all over the world. So, it is known as network of networks. The internet is an information superhighway and has logically connected the world into a cyber-village.History of the Internet: Internet started with the ARPANET in 1969 AD. ARPA is the acronym for Advanced Research Project Agency which is the branch of Department of Defense (DOD) of United States of America. That was the first computer network in the world. Another factor is the rapid growth of this network was the inclusion of the TCP/IP (Transmission Control Protocol/Internet Protocol). It was the first protocol developed by ARPANET. Afterward ARPENET changed into Defense Advanced Research Project Agency (DARPANET). In the mid of 1980, the DOD stopped funding for ARPANET and another agency ‘ National Science Foundation ’ had joined the ARPANET.Services of the Internet:• Electronic Mail• E-commerce

• Video conference• Chatting• E-learning• Entertainment• Marketing and Advertising, etc.Some Common Internet Terminologies:Webpage: Web page is a document stored in an electronic form that contains information in specific or single topic (organization, government agency, personal etc.) using text, graphics, sounds, animated pictures, hyperlinks etc.Website: A collection of interlinked web pages of an organization, government agency, University, Personal, company, etc. is known as website. Each website is identified by the unique Internet Address known as Uniform Resource Locator (URL).Web server: A Web server is a computer that delivers web pages. The web sites are stored in web servers. To access the web pages of a web server, a client computer has to use a HTTP.URL: URL stands for Uniform Resource Locator, the unique Internet address through which we can visit different websites. URLs are used to address and access individual web pages and Internet services or access as well as the access method and the location.

DNS: DNS stands for Domain Name System (or services or server), is an internet service used for converting domain name into IP Address on the internet or on local networks using the TCP/IP.ISP: The Internet Service Provider (ISP) is company or organization that provides Internet facility to the users. The internet can be connected using Integrated Service Digital Network (ISDN), leased line, cable line and satellite connection.Search Engine: Search engine is the website that allows the users to search information based on keyboard or combinations of keywords in different subjects and topics.Web Browser: Web browser is a software or program that accesses web pages and displays them on the user’s computer from around the world. In another terms, it is a software required for browsing and surfing web sites.Intranet and Extranet: Intranet is a privately maintained computer network control by company or an organization. Similarly, Extranet is also private network that uses Internet Protocols, connectivity.

PRESENTATION ON COMPUTER SECURITY AND COMPUTER VIRUSIntroduction:Computer security refers to the protection of the computer’s resources from accidental, intentional or natural disasters, including theft, physical damage, heat, power failure, illegal access, data piracy, virus infection, etc. Computer Security is the branch of computer technology known as information security as applied to computers and networks. The objective of the computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to remain accessible and productive to its intended users.It is further divided into two types:1> Hardware security: Hardware security is the term used to describe the protection of the components of a computer system. In another word, the security given to the various hardware tools and equipment for the protection of computer hardware from the accidental or intentional harm is known as hardware security.

Some Hardware Security Measures are: Dust free environment Regular maintenance Proper Power supply Protection from thieves Insurance Protection from fire Air condition room

2> Software security: Data and software or programs are very important and valuable things of any organizations or computer owners. The lost of these data or programs can cause serious problems to the owners. It is very costly and difficult to recover these important data and some causes that is impossible to recover them. So, data and software security is important for any organization as well as every computer owners. The securing data and programs from being lost or damaged due to accidental or intentional harm is known as software security.Some software security measures are: Protection from computer viruses Password protection Backup System Scandisk, etc.

Computer VirusIntroduction: A computer virus is a small executable program that spreads from one computer to another and interferes with computer operations. A virus programs contains instructions to initiate some sort of “event” that affects the infected computer. Each virus has a unique event associated with it. Virus is destructive program able to replicate itself. This means that the virus multiplies on a computer by making copies of it. This replication is intentional; it is part of the virus program. In most the cases, if a file that contains virus is executed or copied onto another computer, then that computer will also be “infected” by the same virus. A virus can be introduced to a computer system along with any software program. For internet user’s, this threat can come from downloading files or referencing email attachments.Symptoms of computer viruses: Slows down the system performance Program starts automatically without any instructions Programs takes a long time to load suddenly Frequently display unusual error messages or images Computer stops responding or freezes frequently The operating systems will not be loaded when you start your computer

Programs disappear from the computer Random files and icons appearing on your desktop or other places

when you did not install such things Files and icons which were on your system before have disappeared.Effects of viruses: Renaming the files with different names. Reduces memory or disk space of your computer Deletes or changes the contents of our computer Change the size of files and folders Changes the extension of files Disables the antivirus program for no reason Stops the installation of new software programs Crashes and restarts computer in every few seconds Corrupts the system’s file

Different types of computer viruses:1) Program or file Infector virus: Program or file infector virus affects programs or executable

files having an extension .EXE, .BIN, .SYS, .COM, or .DRV. This virus may completely overwrite the file, or may only replace parts of the file that it infects.

2) Boot sector virus: Boot sector virus affects the boot sector or Master boot records (MBR) of a floppy or hard disk.

3) Multipartite virus: Multipartite virus affects the application programs and boot sector of a disk. It has combined features of both boot sector and file infectors viruses.

4) Stealth virus: Stealth virus is one of the most dangerous types of virus which try to trick anti-virus software by intercepting its requests to the operating system.

5) Polymorphic virus: Polymorphic virus is a type of destructive program that can change its appearance with every infection. It is also known as the encrypted virus.

6) Macro virus: Macro virus infects files that are created using word processing or spreadsheet programs which contain macros.

7) Script virus: Script virus infects programs written in high level scripting languages like Visual Basic script and JavaScript. This script virus changes the scripting codes in HTML document and makes the document inaccessible and take longer time to load

8) Trojan Horse: A Trojan Horse is a harmful program that displays as a useful software and does not replicate unlike worm and virus.

9) Worm: A computer worm is a destructive program that replicates from a computer to another computer by spreading entire copies to itself instead of infecting files or operating systems.

Spreading of computer virus: Virus spread by the use of pirated software Viruses spread by sharing of portable disks among the computers Viruses spread by downloading files or programs from unsecure web sites Virus spread by exchanging of infected data or files over networkAntivirus Software: Antivirus software is a program that can detect, prevent and clean up computer viruses which may attempt to infect your computer system. It scans downloaded files as well as the entire computer system in order to detect the presence of an infection. There are a number of good antivirus programs to choose from including Norton Antivirus, McAfee, AVG, Avira, Kaspersky, Avast, NOD 32, etc.Virus Prevention: Use Antivirus Software Don’t open attachments from unknown emails Download software only from reputable and well known sites Don’t use USB flash drive without scanning Clear temporary Internet files and Cache regularly.

PRESENTATION ON CYBER LAW AND COMPUTER ETHICS

Introduction: The law that controls the legal issues in the Internet or WWW for digital data processing and transaction is called cyber law. It is a term that summarizes the legal issues related to use of communicative, transactional, and distributive aspects of networked information devices and technologies. Cyber law is important because it touches almost all aspect of transactions and activities on the cyberspace. It controls cyber crimes and misuse of computer. Virtual space created by world-wide computer network, Internet and telecommunication is called cyber space. Cyberspace was used in 1984 by author William Gibson in his scientific novel ‘Neuromancher’. It is controlled and managed by system of law and regulation called cyber law.

The major laws include in cyber laws are:1) Electronic and Digital Signature law2) Cyber crime law3) Data protection and privacy law4) Tele-communication law5) Intellectual property right lawCyber Crime: The criminal or illegal activities involving the information technology with the help of computers is known as cyber crime. It includes traditional crimes conducted through the internet. Some of the criminal activities are:o Fraud achieved by the manipulation of computer recordso Accessing others data or information illegallyo Copying and disturbing software illegallyo Intellectual Property theft, including software piracyo E-mail bombing, sending large number of mailso Making and digitally disturbing child pornography

The effects of computer crime are: Security problems Physical theft of computers and other devices Very less privacy Destroying Data Computer virus easily attack software and programsCyber Law In Nepal: The main purpose of the formulating cyber law is to legalize the transaction through electronic media, to control and stop the various types of electronic frauds, to punish a person or institution that does cyber crime. It also helps the IT sector to create a suitable environment for conducting and promoting IT business in a country. Cyber law of Nepal was passed in Nepal on 30th Bhadra 2061 BS (15 Sep 2004). The cyber law of Nepal is also known as Electronic Transaction and Digital Signature Act- 2061. The provision of cyber law of Nepal are listed below:• Provision of legal status to digital signatures, electronic record for introducing e-banking, e-

commerce, etc• Provision of network services• Provision for the license regarding the IT customers and their duties and responsibilities• Provision for a legal framework to facilitate and safeguard electronic transactions in the

electronic medium.

Computer Ethics: Ethics deals with placing a “value” on acts according to whether they are “good” or “bad”. Every society has its rules about whether certain acts are ethical or not. These rules have been established as a result of consensus in society and are often written into laws. When Computers first began to be used in society at large, the absence of ethical standards about their use and related issues caused some problems.Some important commandments of computer ethics are mentioned below: Do not use a computer to harm other people Do not use a computer to publish fake information Do not search the file or record of other people Do not destroy or delete the records of other people Do not use a computer to harm other people Do not interfere with other people’s computer work Do not snoop around in other people’s file

Some common Terms:1) Digital Signature: Digital Signature is a security mechanism

system in the cyberspace for digital data transformation by attaching a code on the document of electronic records.

2) Encryption: The method of making the data or message unreadable by unauthorized people while transferring through the Internet is called Encryption.

3) Decryption: The method of converting encrypted data back into its original form make understandable to the receiver is known as decryption.

Internet has grown very fast and security has lagged behind.

Legions of hackers have emerged as impedance to entering the hackers club is low.

It is hard to trace the perpetrator of cyber attacks since the real identities are camouflaged

It is very hard to track down people because of the ubiquity of the network.

Large scale failures of internet can have a catastrophic impact on the economy which relies heavily on electronic transactions

Crisis

In 1988 a "worm program" written by a college student shut down about 10 percent of computers connected to the Internet. This was the beginning of the era of cyber attacks.

Today we have about 10,000 incidents of cyber attacks which are reported and the number grows.

Computer Crime – The Beginning

A 16-year-old music student called Richard Pryce, better known by the hacker alias Datastream Cowboy, is arrested and charged with breaking into hundreds of computers including those at the Griffiths Air Force base, Nasa and the Korean Atomic Research Institute. His online mentor, "Kuji", is never found.

Also this year, a group directed by Russian hackers broke into the computers of Citibank and transferred more than $10 million from customers' accounts. Eventually, Citibank recovered all but $400,000 of the pilfered money.

Computer Crime - 1994

In February, Kevin Mitnick is arrested for a second time. He is charged with stealing 20,000 credit card numbers. He eventually spends four years in jail and on his release his parole conditions demand that he avoid contact with computers and mobile phones.

On November 15, Christopher Pile becomes the first person to be jailed for writing and distributing a computer virus. Mr Pile, who called himself the Black Baron, was sentenced to 18 months in jail.

The US General Accounting Office reveals that US Defense Department computers sustained 250,000 attacks in 1995.

Computer Crime - 1995

In March, the Melissa virus goes on the rampage and wreaks havoc with computers worldwide. After a short investigation, the FBI tracks down and arrests the writer of the virus, a 29-year-old New Jersey computer programmer, David L Smith.

More than 90 percent of large corporations and government agencies were the victims of computer security breaches in 1999

Computer Crime - 1999

In February, some of the most popular websites in the world such as Amazon and Yahoo are almost overwhelmed by being flooded with bogus requests for data.

In May, the ILOVEYOU virus is unleashed and clogs computers worldwide. Over the coming months, variants of the virus are released that manage to catch out companies that didn't do enough to protect themselves.

In October, Microsoft admits that its corporate network has been hacked and source code for future Windows products has been seen.

Computer Crime - 2000

Some of the sites which have been compromised U.S. Department of Commerce NASA CIA Greenpeace Motorola UNICEF Church of Christ …

Some sites which have been rendered ineffective Yahoo Microsoft Amazon …

Why Security?

Because they can A large fraction of hacker attacks have been pranks

Financial Gain Espionage Venting anger at a company or organization Terrorism

Why do Hackers Attack?

Active Attacks Denial of Service Breaking into a site

Intelligence Gathering Resource Usage Deception

Passive Attacks Sniffing

Passwords Network Traffic Sensitive Information

Information Gathering

Types of Hacker Attack

Over the Internet Over LAN Locally Offline Theft Deception

Modes of Hacker Attack

Definition:An attacker alters his identity so that some one

thinks he is some one else Email, User ID, IP Address, … Attacker exploits trust relation between user and

networked machines to gain access to machines

Types of Spoofing:1. IP Spoofing:2. Email Spoofing3. Web Spoofing

Spoofing

Definition:Attacker uses IP address of another computer to acquire information or gain access

IP Spoofing – Flying-Blind Attack

Replies sent back to 10.10.20.30

Spoofed Address10.10.20.30

Attacker10.10.50.50

John10.10.5.5

From Address: 10.10.20.30To Address: 10.10.5.5

• Attacker changes his own IP address to spoofed address

• Attacker can send messages to a machine masquerading as spoofed machine

• Attacker can not receive messages from that machine

Definition:Attacker spoofs the address of another machine and inserts itself between the attacked machine and the spoofed machine to intercept replies

IP Spoofing – Source Routing

Replies sent back to 10.10.20.30

Spoofed Address10.10.20.30

Attacker10.10.50.50

John10.10.5.5

From Address: 10.10.20.30To Address: 10.10.5.5

• The path a packet may change can vary over time • To ensure that he stays in the loop the attacker uses source

routing to ensure that the packet passes through certain nodes on the network

Attacker intercepts packetsas they go to 10.10.20.30

Definition:Attacker sends messages masquerading as some one elseWhat can be the repercussions?

Types of Email Spoofing:1. Create an account with similar email address

– Sanjaygoel@yahoo.com: A message from this account can perplex the students

2. Modify a mail client– Attacker can put in any return address he wants to in the mail

he sends3. Telnet to port 25

– Most mail servers use port 25 for SMTP. Attacker logs on to this port and composes a message for the user.

Email Spoofing

Basic Attacker registers a web address matching an entity e.g.

votebush.com, geproducts.com, gesucks.com Man-in-the-Middle Attack

Attacker acts as a proxy between the web server and the client Attacker has to compromise the router or a node through which

the relevant traffic flows URL Rewriting

Attacker redirects web traffic to another site that is controlled by the attacker

Attacker writes his own web site address before the legitimate link Tracking State

When a user logs on to a site a persistent authentication is maintained

This authentication can be stolen for masquerading as the user

Web Spoofing

Web Site maintains authentication so that the user does not have to authenticate repeatedly

Three types of tracking methods are used: 1. Cookies: Line of text with ID on the users cookie

file– Attacker can read the ID from users cookie file

2. URL Session Tracking: An id is appended to all the links in the website web pages.

– Attacker can guess or read this id and masquerade as user

3. Hidden Form Elements– ID is hidden in form elements which are not visible to

user– Hacker can modify these to masquerade as another user

Web Spoofing – Tracking State

Definition:Process of taking over an existing active session

Modus Operandi:1. User makes a connection to the server by

authenticating using his user ID and password.2. After the users authenticate, they have access to

the server as long as the session lasts.3. Hacker takes the user offline by denial of service4. Hacker gains access to the user by

impersonating the user

Session Hijacking

Attacker can monitor the session periodically inject commands into session launch passive and active attacks from the session

Session Hijacking Bob telnets to Server

Bob authenticates to Server

Bob

Attacker

Server

Die! Hi! I am Bob

Attackers exploit sequence numbers to hijack sessions Sequence numbers are 32-bit counters used to:

tell receiving machines the correct order of packets Tell sender which packets are received and which are lost

Receiver and Sender have their own sequence numbers When two parties communicate the following are needed:

IP addresses Port Numbers Sequence Number

IP addresses and port numbers are easily available so once the attacker gets the server to accept his guesses sequence number he can hijack the session.

Session Hijacking – How Does it Work?

Definition:Attack through which a person can render a system unusable

or significantly slow down the system for legitimate users by overloading the system so that no one else can use it.

Types:1. Crashing the system or network

– Send the victim data or packets which will cause system to crash or reboot.

2. Exhausting the resources by flooding the system or network with information

– Since all resources are exhausted others are denied access to the resources

3. Distributed DOS attacks are coordinated denial of service attacks involving several people and/or machines to launch attacks

Denial of Service (DOS) Attack

Types:1. Ping of Death2. SSPing3. Land4. Smurf5. SYN Flood6. CPU Hog7. Win Nuke8. RPC Locator9. Jolt210. Bubonic11. Microsoft Incomplete TCP/IP Packet Vulnerability12. HP Openview Node Manager SNMP DOS Vulneability13. Netscreen Firewall DOS Vulnerability14. Checkpoint Firewall DOS Vulnerability

Denial of Service (DOS) Attack

This attack takes advantage of the way in which information is stored by computer programs

An attacker tries to store more information on the stack than the size of the buffer

How does it work?

Buffer Overflow Attacks

• Buffer 2

Local Variable 2Buffer 1

Local Variable 1

Return Pointer

Function Call Arguments

•

FillDirection

Bottom ofMemory

Top ofMemory

Normal Stack

• Buffer 2

Local Variable 2Machine Code:execve(/bin/sh)New Pointer to

Exec CodeFunction Call

Arguments

•

FillDirection

Bottom ofMemory

Top ofMemory

Smashed Stack

Return Pointer Overwritten

Buffer 1 Space Overwritten

Programs which do not do not have a rigorous memory check in the code are vulnerable to this attack

Simple weaknesses can be exploited If memory allocated for name is 50 characters, someone can

break the system by sending a fictitious name of more than 50 characters

Can be used for espionage, denial of service or compromising the integrity of the data

Examples NetMeeting Buffer Overflow Outlook Buffer Overflow AOL Instant Messenger Buffer Overflow SQL Server 2000 Extended Stored Procedure Buffer Overflow

Buffer Overflow Attacks

A hacker can exploit a weak passwords & uncontrolled network modems easily

Steps Hacker gets the phone number of a company Hacker runs war dialer program

If original number is 555-5532 he runs all numbers in the 555-55xx range

When modem answers he records the phone number of modem

Hacker now needs a user id and password to enter company network

Companies often have default accounts e.g. temp, anonymous with no password

Often the root account uses company name as the password For strong passwords password cracking techniques exist

Password Attacks

Password hashed and stored Salt added to randomize password & stored on system

Password attacks launched to crack encrypted password

Password Security

HashFunction

Hashed Password

Salt

ComparePassword

Client

Password

Server

Stored Password

Hashed Password

Allow/Deny Access

Find a valid user ID Create a list of possible passwords Rank the passwords from high probability to

low Type in each password If the system allows you in – success ! If not, try again, being careful not to exceed

password lockout (the number of times you can guess a wrong password before the system shuts down and won’t let you try any more)

Password Attacks - Process

Dictionary Attack Hacker tries all words in dictionary to crack password 70% of the people use dictionary words as passwords

Brute Force Attack Try all permutations of the letters & symbols in the alphabet

Hybrid Attack Words from dictionary and their variations used in attack

Social Engineering People write passwords in different places People disclose passwords naively to others

Shoulder Surfing Hackers slyly watch over peoples shoulders to steal passwords

Dumpster Diving People dump their trash papers in garbage which may contain

information to crack passwords

Password Attacks - Types