1. Computer Science 1 Week 6

2. This Week ... QBasic Programming Computer Concepts Input Statements
Viruses
Worms
Trojans
Spyware

4. QBasic Input Statements
Getting data from the user

5. Functions of a Computer
Process Data
Input Data
Store Data
Output Data

6. Input Statement What it does It can display a prompt
pauses the program
inputs from the keyboard
assigns it to a variable
It can display a prompt
must be a string literal
it is optional

7. Input Statement Syntax
INPUT Prompt, Variables
Optional

8. Example Program DIM User AS STRING INPUT "Name:", User
PRINT "Hello "; User
Prompt
Variable

9. Example Program: What happens?
Memory:
DIM User AS STRING
INPUT "Name:", User

10. Example Program: What happens?
Memory:
User
DIM User AS STRING
INPUT "Name:", User

11. Example Program: What happens?
Memory:
User
Moe
DIM User AS STRING
INPUT "Name:", User

12. Example Program: What happens?
Memory:
User
Moe
DIM User AS STRING
INPUT "Name:", User

13. Example Program DIM User AS STRING INPUT "Name:", User
PRINT "Hello "; User
"Moe"

14. Example Program Output
Name: Moe
Hello Moe
Prompt &
Your Input

15. Example Program 2 DIM Greek AS String INPUT "Pledge:", Greek
PRINT Greek

16. Example Program 2 Output
Pledge: Cuppa Kappa Chino
Cuppa Kappa Chino

17. Example Program 3
INPUT "First:", F
INPUT "Last:", L
PRINT F ; " " ; L

18. Example Program 3 Output
First: Joe
Last: Gunchy
Joe Gunchy

19. Example Program 4 PRINT "Enter Your Name" INPUT "Name:", You PRINT
PRINT "Hey "; You; "!"

20. Example Program 4 Output
Enter Your Name
Name: Curly
Hey Curly!

21. Example Program 5 INPUT "Height:", Feet LET Meters = Feet * 0.3048
PRINT "Meters:"; Meters

22. Example Program 5 Output
Height: 6
Meters:

23. Example Program 6 INPUT "Diameter:", D
LET V = 4 / 3 * 3.14 * (D / 2) ^ 3
LET W = V * 2.5
PRINT "Each weighs" ; W

24. Example Program 6 Output
Diameter: 3
Each weighs

25. Cls Statement Review Used to clear the screen
Any information on the output screen will disappear

26. Cls Example
PRINT "You will see me."
CLS
PRINT "Where are you?"

27. Output before CLS was cleared
Cls Example
Where are you?
Output before CLS was cleared

28. Input Statements – Silly Sentences
QBasic Lab
Input Statements – Silly Sentences

29. This week ... You will make a game! It's called Silly Sentences
players create a sentence
it requires 2 human players

30. The Game Each player takes turns
they cannot look at what the other player is typing
each player enters part of a sentence
Then the completed sentence is displayed
it can be silly
... or completely ludicrous

31. Program Flow Player A enters a Noun Player B enters a Verb
Player A enters a Preposition
Player B enters a Noun
Finally, print the complete sentence

32. Volunteers Please ...

33. You Will Need to Use... The CLS statement Four INPUT statements
clear the screen between each turn
... so the other player can't see what you typed
Four INPUT statements
at least 4 variables
one for the verb, preposition and the two nouns.
PRINT statement to display the sentence

34. Remember ... Turn your program
to Lab5 at SacCT
If you do not turn in your program, you will not get credit!

36. How to Make Your Programs SHINE
Programming Tips
How to Make Your Programs SHINE

37. Structure Your Program
It will be easier to write and read
Good General Format
Put your declarations first
Then put your logic statements
Finally, create your output

38. Assign values and Processing
Good General Format
DIM Statements
………
LET Statements
INPUT ……
PRINT Statements
Declare variables
Assign values and Processing
Output

39. Example: Area of a Circle
DIM Radius
DIM Area
LET Radius = 4
LET Area = 3.14 * Radius ^ 2
PRINT "Area is"; Area

41. Basics of Dangerous Software
Malicious Software
Basics of Dangerous Software

42. Malware Malware refers to any malicious software
designed to damage or destroy data
designed to steal data
designed to scam or extort the user
Often misuses legitimate technology
ActiveX
JavaScript, Visual Basic Script

43. Misused Technology: Microsoft ActiveX
allows a program to be used with a web page
designed to keep computers up to date
software can be automatically downloaded
Severe security risk
the downloaded software might be malicious
often used by spyware companies

44. Misused Technology: JavaScript
easy to use scripting language
designed to add functionality to webpages
examples: mouseovers, interactive menus, etc ...
Can create pop-ups
you can be exposed to spyware
these can be stopped with a pop-up blocker

45. Trojans Named after the Trojan Horse A hidden part of some useful s/w
pretends to be legitimate software
... but it performs "secret" actions
Can carry other malicious code
Does not replicate itself
Modify, delete files,
send files via , start a worm outbreak, install spyware, use infected computers to send out spams, …

46. Worms Named after a tapeworm It breaks into your computer
Spread by exploiting a vulnerable network port
Vulnerable network application to which attacker can send worm
Worms
Named after a tapeworm
It breaks into your computer
transports itself over a network
does not need a host document
self-replicating
enters a computer without a user interaction!
Often delivers malware
Allow creator to remotely install s/w for sending spam, stealing ID, directing users to online scam/phishing sites
Mass mailing, botnets
Website defaced
Denial of service attack
System shutdown, …………

48. Fatal Computer Diseases
Viruses
Fatal Computer Diseases

49. Viruses These are malicious programs that ... Key characteristics:
can attach themselves to a file
reproduce themselves – make copies
Key characteristics:
requires some user interaction (e.g., click an attachment, or a Word document)
hide on a computer and spread
can be dormant for days or months
can have a trigger event

50. Symptoms of a Virus Infection
Files
files are deleted and/or modified
files "appear" out of nowhere
Performance degradation
Application software changes
some applications disappear
browser reconfiguration

51. Common Virus Variants File virus Macro virus / Script virus
attaches itself to an application program
not as common now as in the past
Macro virus / Script virus
infects users by running a script
misuses scripting technology
e.g. the "I Love You" virus

52. The ILOVEYOU Virus Attacked in May, 2000 Global epidemic!
Came as an
titled simply I Love You
it came from someone you know!
came with an attachment
LOVE-LETTER-FOR-YOU.TXT.vbs

53. The ILOVEYOU Virus: How it attacked
Attachment was active
Visual Basic Script file
used Windows Scripting Host
no security – full control on your computer!

54. The ILOVEYOU Virus: What it did
Sent copies of itself to everyone in your Outlook list
Infected your computer
replaced all JPG, JPEG, etc..
new file had same name - kinda
parents.jpg  parents.jpg.vbs

56. Anti-malware Software
Curing the Computer Disease

57. Antivirus Software Utility programs that Examples
look for viruses, worms, etc...
protects you from infection
runs all the time – system software
Examples
McAfee
Symantec

58. Approaches
Real-time protection against installing malware on a computer
Scan incoming data from network for malware and block threats as it comes across
Detect and remove malware
scan OS files and installed programs and report identified malware

59. How Antivirus Software Works
Keeps track of existing files
some viruses can insert themselves into unused portions of a program
software creates a checksum to watch for changes
Checks for a virus signature
unique series of bytes used to identify a virus
this information is continuously updated

60. Reliability of Antivirus Software
Some viruses are extremely sophisticated
Stealth viruses – leave no signature...
self-modifying – change the signature each time
polymorphic – encrypt randomly
metamorphic – they rewrite themselves!
Something might slip through!

62. It is watching you & stealing your data
Spyware & Adware
It is watching you & stealing your data

63. What is Spyware? Malicious software designed to:
secretly track your activity
steal your passwords and personal data
Exploits you to make money
often displays pop-up windows
your data can be sold on the black-market

64. Adware vs. Spyware Adware displays advertisements Differences:
to support a free product
often the ad is part of the application
Differences:
adware does not track your activity
adware does not steal your information

65. Spyware vs. Viruses Viruses Spyware often written by individuals
Keylogger: password, ID, credit card, keys to online games, online banking info, web-surfing habits
Dialer, taking control of dial-up modem and charging toll
Redirect search engine results to paid advertisements
Overwrite affiliate marketing codes so that revenue is redirected to spyware creator
…………
Viruses
often written by individuals
often designed to destroy data
Spyware
created by computer companies
designed to steal data

66. Symptoms of Spyware Continuous pop-up windows Start Page Hijacking
often based on a website's content
may even appear when you are not using a browser
Start Page Hijacking
your start page changes & you cannot change it!
the page is related to the spyware

67. Symptoms of Spyware Poor performance Software appears out of nowhere
computer becomes slow and/or unstable
your Internet connection becomes slow
Software appears out of nowhere
spyware can install software on your computer without your permission
in particular, toolbars are added to your browser

69. SEVERE
INFESTATION

70. Things You Won't Detect Key Logger Online Tracking
record everything you type
can get your passwords
Online Tracking
what websites you visit
what you use

72. How it gets on your computer
How Spyware Installs
How it gets on your computer

73. How You Get Infested Hidden is some free software
software distributor gets money from the spyware maker
software distributor tends to be unscrupulous
Website links to an executable
the link will open an installation program!
never open a link that ends in .exe!!!

74. How You Get Infested Drive-by downloads Worm attack
misuse of ActiveX technology
website prompts you to download - maybe
Worm attack
spyware is downloaded and installed secretly
exploits any bugs in browsers, networks, etc...
often misuses ActiveX technology

75. Read the License!

77. ActiveX Download
Always
select "No"!

79. Spyware & Adware Gallery
Some Spyware & Adware Applications

80. Webroot's Spyware Top 10 CoolWebSearch Virtumonde Hotbar / Zango
PurityScan
Comet Cursor

81. Webroot's Spyware Top 10 180search Assistant / Zango Maxifiles
Starware Toolbar
System Doctor
ZenoSearchAssistant

82. CoolWebSearch Creators unknown Over 60 variants – all terrible
What it does
displays pop-ups – sometimes porn
hijacks start page on browser
redirects pages to other spyware pages
may change desktop

83. CoolWebSearch Some variants
DataNotary
hijacks start page to datanotary.com
scans for porn
BootConf
hijacks start page to coolwebsearch.com
hijacks searches
damages the computer's security

84. CoolWebSearch Some variants
MSInfo
hijacks start page to true-counter.com
hijacks searches to global-finder.com
PNP
hijacks start page to adulthyperlinks.com and allhyperlinks.com
hides where Windows stores driver data

85. Zango Created by 180 Solutions Sues anyone that calls it "spyware"
very recently sued Zone Labs
lawsuit was dropped
Names:
was originally called “180 Search Assistant”
Seekmo (a.k.a. Seeko)

86. Zango How it gets installed What is does
offers a toolbar with a search feature
has a “free” instant messenger
their website tricks users into opening an executable
What is does
displays pop-ups
transmits your browsing history
attempts to reinstall itself

87. Virtumonde / Vundo Spyware & Rogueware How it gets installed
attachment
browser security flaws – Java, etc....
drive-by downloads

88. Virtumonde / Vundo What it does
pop-ups saying your computer is unstable
screensaver changed to blue screen of death
hijacks start page
hijacks searches to spyware sites
changes the desktop – icon, wallpaper

89. Virtumonde / Vundo What it does – ATTACK ON SECURITY
deletes security software!
attempts to hide – massive loss of hard disk space
Safe Mode is damaged – blue screen of death
prevents downloading software it doesn't like
damages the Windows Control Panel
will reinstall itself

90. More Examples (a few old)
ISTBar
Hot as Hell
Advanced Keylogger
TIBS Dialer
Claria Gator

91. Hot as Hell & TIBS Dialer
How they get installed
required to use some porn websites
the user downloads the software for access
What they do:
dials 900-numbers when you are away
can cost you thousands of dollars

92. Advanced Keylogger Created by ELTIMA Software
a.k.a "SoftInfinity Advanced Keylogger"
What it does
records every key you press
sends s
captures screenshots of your computer
The software is sold to anyone

93. IST Bar Created by Integrated Search Technologies
How it gets installed
drive-by download and JavaScript tricks
offers a number of toolbars that claim to help searches
bundled with some free software

94. IST Bar What it does displays pop-ups transmits your browsing history
hijacks your browser
downloads software

95. IST Bar Some of IST's toolbars Search Assistant – a.k.a. Side Find
Slotch Bar
Toolbar Cash
Your Site Bar