Transcript
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Computer SecurityStd XIChapter 8
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Security Principles
During
Data Transmission on theInternet
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Confidentiality
Content of the message
should be accessed by Sender &
Recipient
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Integrity
Message/data must arrive
exactly as it was sent
NO modification done either
accidentally or maliciously
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Authentication
Receiver must be sure of thesenders identity
All users must have a
user ID &
password
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Nonrepudiation
A sender must not denyhaving sent the message to
the receiver
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For security
Encryption and Decryptionare used.
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Destructive software Viruses
Malware
Spyware
Worms
Browser Hijackers Spam
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Viruses
Vital Information
Resources Under
Seize
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Viruses
Cannotaffect
hardware
Attacks
software
such asO.S.
application
softwaree-mails
data
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Types ofViruses
Boot sector virus
Macro virus
E-mail virus
File infector virus (.com,.exe, .sys, .ovl, .prg, .mnu)
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How the virus works
Clean uninfectedprogram
Virus Infectedprogram
Compute A , B
Perform printing
End
Compute A , B
Delete all files
Corrupt data
Send copy of virus
to all programs
Perform printing
End
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Malware & Spyware
performs malicious action w/o
users permission
Spyware gathers information
relays info to advertisers & others
installed w/o consent, knowledge(click, pop-up) (adware)
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Worms
Replicateyourself
Replicate
yourself
Replicateyourself
Replicate
yourself
Replicate
yourself
Replicate
yourself
Replicate
yourself
Replicate
yourself
Replicate
yourself
Replicate
yourself
No destruction
Eat up
Computersresources
Make the
computer
unusable
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Trojan Horse Is not self replicatingmain purpose is not make
modifications in the target computer
Requires interaction with the hacker
Reveals confidential info (user ID,
pwd)Allows hackers remote access to
target system
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Browser Hijackers alters your browser settings redirects home page to rogue search
engines
With sponsored links as results (hit list)
Could also direct the browser to an
error pageForces hits
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Spam abuse of e-mail unsolicited mail, bulk e-mail (UBE)
Commercial content
Use of spam guard
Spammers collect e-mail addresses
from chatrooms, websites, customer lists,newsgroups, and viruses which harvest
users' address books,
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Antivirus
protection from virus,
worm, trojan horse, malware can be purchased or
downloaded
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Commercial Antivirus
softwareAVG
BitDefender
Norton
McAfee
KasperskyeScan
K7
Bull Guard
Dr.Web
Panda Security
PC Tools
Protector PlusRising
ZoneAlarm
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Freely available Antivirus
softwareAOL ActiveVirus Shield
AVG AntivirusFree Avast Home
Bitdefender 8
free edition
Comodo
McAfee
VirusScan Plus
PC Tools AntiVirusFree Edition
Dr.Web Cureit!
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Antivirus software
downloadsClamClamWin
Moon Secure
Open
WinpoochAbandonware
Aidstest
Antiviral Toolkit
Pro
Central PointdLight
Dr. Solomons
The Antidote
Thunderbyte
Turbo
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Preventive MeasuresDo not open e-mail attachmentsUpdate anti-virus software regularly
Delete chain letters, forward, virus
alerts and junk mail
When Downloading files if unsure of
their authenticity, scan them firstBackup regularly
Do not hide file extensions
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Preventive Measures
Do not download files from strangers
If you have to then download to a
removable disk and scan with antivirus
Protect using Internet firewall
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To Turn on Firewall
Click start
Control Panel
Security Center
Windows firewall
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For Unhiding File
Extensions Click My Computer
Tools Menu Folder Options
View tab
Uncheck Hide extensions
for known file types
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Lab Exercise Find names of Trojan Horses
Find names of Viruses
Find names of Worms Find details of Malware
Find details of spyware
Find names of Browser Hijackers
Anti Virus scanning procedure
details
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