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Introduction to Computing

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Introduction to Computing ­ CS101
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LESSON 39
CYBER CRIME
Focus of the last Lesson was on Database SW
·
In our final Lesson on productivity SW, we continued our discussion on data management
·
We found out about relational databases
·
We also implemented a simple relational database
Relational Databases
·
Databases consisting of two or more related tables are called relational databases
·
Each column of those tables can contain only a single type of data (contrast this with spreadsheet
columns!)
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Table rows are called records; row elements are called fields
·
A relational database stores all its data inside tables, and nowhere else
·
All operations on data are done on those tables or those that are generated by table operations
·
Tables, tables, and nothing but tables!
RDBMS
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Relational DBMS software
·
Examples:
­
Access
­
FileMaker Pro
­
SQL Server
­
Oracle
Classification of DBMS w.r.t. Size
·
Personal/Desktop/Single-user (MB-GB)
·
Server-based/Multi-user/Enterprise (GB-TB)
·
Seriously-huge databases (TB-PB-XB)
The Trouble with Relational DBs
·
Much of current SW development is done using the object-oriented methodology
·
When we want to store the object-oriented data into an RDBMS, it needs to be translated into
a form suitable for RDBMS
·
Then when we need to read the data back from the RDBMS, the data needs to be translated back
into an object-oriented form before use
·
These two processing delays, the associated processing, and time spent in writing and maintaining
the translation code are the key disadvantages of the current RDBMSes
Some Terminology
·
Primary Key is a field that uniquely identifies each record stored in a table
·
Queries are used to view, change, and analyze data. They can be used to:
­
Combine data from different tables, efficiently
­
Extract the exact data that is desired
·
Forms can be used for entering, editing, or viewing data, one record at a time
·
Reports are an effective, user-friendly way of presenting data. All DBMSes provide tools for
producing custom reports
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Introduction to Computing ­ CS101
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Desktop RDBMS Demo
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We will create a new relational database
·
It will consist of two tables
·
We will populate those tables
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We will generate a report after combining the data from the two tables
Today's Lecture:
Cyber Crime
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To find out about several types of crimes that occur over cyber space (i.e. the Internet)
·
To familiarize ourselves with with several methods that can be used to minimize the ill effects of
those crimes
39.1 07 February 2000
·
Users trying to get on to the Web sites of Yahoo, couldn't!
·
Reason: Their servers were extremely busy!
·
They were experiencing a huge number of hits
·
The hit-rate was superior to the case when a grave incident (e.g. 9/11) occurs, and people are trying
to get info about what has happened
·
The only problem was that nothing of note had taken place!
What was going on?
·
A coordinated, distributed DoS (Denial of Service) attack was taking place
·
Traffic reached 1 GB/s; many times of normal!
·
In the weeks leading to the attack, there was a noticeable rise in the number of scans that Internet
servers were receiving
·
Many of these scans appeared to originate from IP addresses that traced back to Korea, Indonesia,
Taiwan, Australia
Three Phases of the DoS
1.Search
2.Arm
3.Attack
1. Search for Drones
·
The attackers set about acquiring the control over the computers to be used in the attack ...
·
by scanning ­ using e.g. Sscan SW ­ a large numbers of computers attached to the Internet
·
Once a computer with a weak security scheme is identified, the attackers try a break-in
·
Once conquered, that computer ­ called a drone ­ will be used to scan others
2. Arming the Drones
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After several drones have been conquered, the DoS SW is loaded on to them
·
Examples: Tribal Flood Network, Trinoo, TFN2K
·
Like a time-bomb, that SW can be set to bring itself into action at a specified time
·
Alternatively, it can wait for a commencement command from the attacker
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Introduction to Computing ­ CS101
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3. The Actual Attack
·
At the pre-specified time or on command, the SW implanted on all of the drones wakes-up and
starts sending a huge number of messages to the targeted servers
·
Responding to those messages overburdens the targeted servers and they become unable to perform
their normal functions
Neutralizing the Attack
·
The engineers responsible for monitoring the traffic on the Yahoo Web sites quickly identified the
key characteristics of the packets originating from those drones
·
Then they setup filters that blocked all those packets
·
It took them around 3 hours to identify and block most of the hostile packets
·
BTW, the sender's IP address can be spoofed, making it impossible to block the attack just by
blocking the IP addresses
The Aftermath
·
None of the Yahoo computers got broken-into; The attackers never intended to do that
·
None of the user data (eMail, credit card numbers, etc.) was compromised
·
Ill-effects:
­  Yahoo lost a few million's worth of business
­  Millions of her customers got annoyed as they could not access their eMail and other info from the
Yahoo Web sites
Who Done It?
·
The DoS SW is not custom SW, and can be downloaded from the Internet. Therefore, it is difficult
to track the person who launched the attack by analyzing that SW
·
After installing the DoS SW on the drones, setting the target computer and time, the attackers
carefully wipe away any info on the drone that can be used to track them down
·
End result: Almost impossible to track and punish clever attackers
How to stop DoS attacks from taking place?
·
Design SW that monitors incoming packets, and on noticing a sudden increase in the number of
similar packets, blocks them
·
Convince system administrators all over the world to secure their servers in such a way that they
cannot be used as drones
·
BTW, the same type of attack brought down the CNN, Buy, eBay, Amazon Web sites the very next
day of the Yahoo attack
39.2 DoS Attack: A Cyber Crime
·
DoS is a crime, but of a new type - made possible by the existence of the Internet
·
A new type of policing and legal system is required to tackle such crimes and their perpetrators
·
Internet does not know any geographical boundaries, therefore jurisdiction is a key issue when
prosecuting the cyber-criminal
Cyber crime can be used to ...
·
Damage a home computer
·
Bring down a business
·
Weaken the telecom, financial, or even defense-related systems of a country
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Introduction to Computing ­ CS101
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Cyberwar!
·
In 1997, blackouts hit New York City, Los Angeles
·
The 911 (emergency help) service of Chicago was shut down
·
A US Navy warship came under the control of a group of hackers
·
What was happening? A cyber attack!
·
All of the above did not happen in reality, but in a realistic simulation
·
The US National Security Agency hired 35 hackers to attack the DoD's 40,000 computer networks
·
By the end of the exercise, the hackers had gained root-level (the highest-level!) access to at least 3
dozen among those networks
Cyberwarfare:
A clear and present threat as well opportunity for all of the world's armed force!
39.3 More cybercrimes ...
Mail Bombing
·
Similar in some ways to a DoS attack
·
A stream of large-sized eMails are sent to an address, overloading the destination account
·
This can potentially shut-down a poorly-designed eMail system or tie up the telecom channel for
long periods
·
Defense: eMail filtering
Break-Ins
·
Hackers are always trying to break-in into Internet-connected computers to steal info or plant
malicious programs
·
Defense: Intrusion detectors
Credit Card Fraud
·
A thief somehow breaks into an eCommerce server and gets hold of credit numbers and related
info
·
The thief then uses that info to order stuff on the Internet
·
Alternatively, the thief may auction the credit card info on certain Web sites setup just for that
purpose
·
Defense: Use single-use credit card numbers for your Internet transactions
Software Piracy
·
Using a piece of SW without the author's permission or employing it for uses not allowed by the
author is SW piracy
·
For whatever reason, many computer users do not consider it to be a serious crime, but it is!
·
Only the large rings of illegal SW distributors are ever caught and brought to justice
·
Defense: Various authentication schemes. They, however, are seldom used as they generally
annoy the genuine users
Industrial Espionage
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Spies of one business monitoring the network traffic of their competitors
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Introduction to Computing ­ CS101
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They are generally looking for info on future products, marketing strategies, and even financial
info
·
Defense: Private networks, encryption, network sniffers
Web Store Spoofing
·
A fake Web store (e.g. an online bookstore) is built
·
Customers somehow find that Web site and place their orders, giving away their credit card info in
the process
·
The collected credit card info is either auctioned on the Web or used to buy goods and services on
the Web
39.4 Viruses
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Self-replicating SW that eludes detection and is designed to attach itself to other files
·
Infects files on a computers through:
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Floppy disks, CD-ROMs, or other storage media
­
The Internet or other networks
·
Viruses cause tens of billions of dollars of damage each year
·
One such incident in 2001 ­ the LoveBug virus ­ had an estimated cleanup/lost productivity cost of
US$8.75 billion
·
The first virus that spread world-wide was the Brain virus, and was allegedly designed by someone
in Lahore
One Way of Classifying Viruses
·
Malicious
­
The type that grabs most headlines
­
May destroy or broadcast private data
­
May clog-up the communication channels
­
May tie-up the uP to stop it from doing useful work
Neutral
­  May display an annoying, but harmless message
Helpful
­  May hop from one computer to another while searching for and destroying malicious viruses
Anatomy of a Virus
·
A virus consists of 2 parts:
·
Transmission mechanism
·
Payload
Transmission Mechanism
·
Viruses attach themselves to other computer programs or data files (termed as hosts)
·
They move from one computer to another with the hosts and spring into action when the host is
executed or opened
Payload
·
The part of the virus that generally consists of malicious computer instructions
·
The part generally has two further components:
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Introduction to Computing ­ CS101
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Infection propagation component:
·
This component transfers the virus to other files residing on the computer
­
Actual destructive component:
·
This component destroys data or performs or other harmful operations
Commonsense Guidelines
·
Download SW from trusted sites only
·
Do not open attachments of unsolicited eMails
·
Use floppy disks and CDROMs that have been used in trusted computers only
·
When transferring files from your computer to another, use the write-protection notches
·
Stay away from pirated SW
·
Regularly back your data up
·
Install Antivirus SW; keep it and its virus definitions updated
Antivirus SW
·
Designed for detecting viruses & inoculating
·
Continuously monitors a computer for known viruses and for other tell-tale signs like:
­  Most ­ but, unfortunately not all ­ viruses increase the size of the file they infect
­  Hard disk reformatting commands
­  Rewriting of the boot sector of a hard disk
·
The moment it detects an infected file, it can automatically inoculate it, or failing that, erase it
39.5 Other Virus-Like Programs
·
There are other computer programs that are similar to viruses in some ways but different in some
others
·
Three types:
­  Trojan horses
­  Logic- or time-bombs
­  Worms
Trojan Horses
·
Unlike viruses, they are stand-alone programs
·
The look like what they are not
·
They appear to be something interesting and harmless (e.g. a game) but when they are executed,
destruction results
Logic- or Time-Bombs
·
It executes its payload when a predetermined event occurs
·
Example events:
·
A particular word or phrase is typed
­  A particular date or time is reached
Worms
·
Harmless in the sense that they only make copies of themselves on the infected computer
·
Harmful in the sense that it can use up available computer resources (i.e. memory, storage,
processing), making it slow or even completely useless
·
Designing, writing, or propagating malicious code or participating in any of the fore-mentioned
activities can result in criminal prosecution, which in turn, may lead to jail terms and fines!
Today's Lecture:
·
We found out about several types of computer crimes that occur over cyber space
·
We familiarized ourselves with with several methods that can be used to minimize the ill effects of
these crimes
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Introduction to Computing ­ CS101
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Next Lecture' Goals
(Social Implications of Computing)
We will explore the impact of computing on:
Business
Work
Living
Health
Education
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Table of Contents:
  1. INTRODUCTION
  2. EVOLUTION OF COMPUTING
  3. World Wide Web, Web’s structure, genesis, its evolution
  4. Types of Computers, Components, Parts of Computers
  5. List of Parts of Computers
  6. Develop your Personal Web Page: HTML
  7. Microprocessor, Bus interface unit, Data & instruction cache memory, ALU
  8. Number systems, binary numbers, NOT, AND, OR and XOR logic operations
  9. structure of HTML tags, types of lists in web development
  10. COMPUTER SOFTWARE: Operating Systems, Device Drivers, Trialware
  11. Operating System: functions, components, types of operating systems
  12. Forms on Web pages, Components of Forms, building interactive Forms
  13. APPLICATION SOFTWARE: Scientific, engineering, graphics, Business, Productivity, Entertainment, Educational Software
  14. WORD PROCESSING: Common functions of word processors, desktop publishing
  15. Interactivity to Forms, JavaScript, server-side scripts
  16. ALGORITHMS
  17. ALGORITHMS: Pseudo code, Flowcharts
  18. JavaScript and client-side scripting, objects in JavaScript
  19. Low, High-Level, interpreted, compiled, structured & object-oriented programming languages
  20. Software Design and Development Methodologies
  21. DATA TYPES & OPERATORS
  22. SPREADSHEETS
  23. FLOW CONTROL & LOOPS
  24. DESIGN HEURISTICS. Rule of thumb learned through trial & error
  25. WEB DESIGN FOR USABILITY
  26. ARRAYS
  27. COMPUTER NETWORKS: types of networks, networking topologies and protocols
  28. THE INTERNET
  29. Variables: Local and Global Variables
  30. Internet Services: FTP, Telnet, Web, eMail, Instant messaging, VoIP
  31. DEVELOPING PRESENTATIONS: Effective Multimedia Presentations
  32. Event Handlers
  33. GRAPHICS & ANIMATION
  34. INTELLIGENT SYSTEMS: techniques for designing Artificial Intelligent Systems
  35. Mathematical Functions in JavaScript
  36. DATA MANAGEMENT
  37. DATABASE SOFTWARE: Data Security, Data Integrity, Integrity, Accessibility, DBMS
  38. String Manipulations:
  39. CYBER CRIME
  40. Social Implications of Computing
  41. IMAGES & ANIMATION
  42. THE COMPUTING PROFESSION
  43. THE FUTURE OF COMPUTING
  44. PROGRAMMING METHODOLOGY
  45. REVIEW & WRAP-UP of Introduction to Computing