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Transcript of Computer Security
Computer Security
CPEs for CPAs Program
Georgia Perimeter College
December 9, 2005
Today’s Topics
The Need for Computer Security
Setting Up a Secure Computer System
Using Your Computer Securely
Special Concerns for Wireless Networks
Today’s Topics
Focus onQuality and effectivenessFree or low-cost solutionsEase of use
The Need for Computer Security
Computers face a wide variety of threats IntrusionsPrivacy invasionsHijackingsData corruptionVirusesAnd more
The Need for Computer Security (cont.)
Threats come from many sourcesPhysical accessNetwork accessUse of removable mediaUse of common programs
http://media.trendmicro.com/product/general/malware.html
How to Keep a System Perfectly Secure
Don’t connect it to any type of networkDon’t use emailDon’t have Internet accessDon’t shop onlineDon’t bank onlineDon’t share files with other users
How to Keep a System Perfectly Secure (cont.)
Don’t use any removable mediaFloppy disksCDs/DVDsFlash Drives/USB devices
Exception: New, unused CDs for backup of data
How to Keep a System Perfectly Secure (cont.)
Don’t let anyone but yourself ever use the computer
Permanently secure it to the building structure
Okay, this may not be feasible!
So what do we do?
What about security for the REST of us?
Setting Up a Secure System
Three Critical StepsAccess Control / Password ProtectionHardware SolutionsSoftware Solutions
Access Control
Simple solution to some problems
No cost involved
Only handles some problems
Password Protection
Set up login password on ALL computersHandled in operating systemDo not allow a “guest” account on
computersWith Windows, accounts can be bypassedNever allow automatic login
Password Protection (cont.)
Extra protection desirable for laptopsSet up BIOS password
Power onHit designated key when prompt appears (must
do quickly)Locate password option on BIOS screen
Caution: if you forget this password, NO ONE can get into your computer
Hardware Solutions
Acts as “first line of defense” by controlling network access
Only protects from external threats
Does not protect against invasion from within network itself
Does not protect against threats hidden inside legitimate data
Hardware Firewall
Monitors network data transfersLANs Internet
Blocks unauthorized traffic while allowing legitimate traffic
May also perform additional security functions
Hardware Firewall (cont.)
Any computer connected to Internet needs a firewallBroadband connections are more
vulnerableEven dial-up users can be attacked from
outside
Hardware Firewall (cont.)
Makes your computer “invisible” from outside the local network
Often found as part of network routing device
Invaders “see” the router, not computers behind it
Hardware Firewall (cont.)
Install between computers and modem in a local network
Internet Connection
RouterModem
Computer Computer Computer
Hardware Firewall (cont.)
Setup and configuration depends on specific device
Follow directions given by manufacturer
Hardware Firewall (cont.)
Solution for the truly paranoid, or the truly geeky
Bare-bones machine running Linux instead of Windows, combined with switch to connect machines
Hardware Firewall (cont.)
Most hacking attacks target Windows features
Using Linux machine instead of router prevents these attacks
For information and instructions: Router Design Project,
http://www.routerdesign.com Coyote Linux Project,
http://www.coyotelinux.com
Software Solutions
Software firewalls
Anti-virus software
Anti-malware software
Alternatives to common programs
Fixes for common programs
Software Firewalls
Not a replacement for hardware firewalls
Protect individual computers within a networkHardware firewall protects entire network
Protect portable machines which may not always use a hardware firewall
Software Firewalls (cont.)
Analyze incoming data from network
Block undesirable data
Better programs block undesirable outgoing data as well
Software Firewalls (cont.)
Windows XP Internet Connection Firewall (ICF)Monitors/blocks incoming traffic onlyWill NOT block hijack attemptsBetter than nothing but not an optimal
solution
Software Firewalls (cont.)
ZoneAlarm – top choiceMonitors traffic in both directionsHelps prevent hijacking of your computerBasic free version is adequate for most
users
Software Firewalls (cont.)
Download from http://www.zonealarm.com/
Install via wizard
ConfigurationDone through normal computer usageDoes take time
Anti-Virus/Anti-Spyware Software
Viruses and spyware are two different problemsBoth technologies can cause problemsRequire two different solutions
Anti-Virus Software
Virus -- n : a software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer; "a true virus cannot spread to another computer without human assistance"
-- dictionary.com
Anti-Virus Software (cont.)
AVG AntiVirusFree for personal useMay not provide quality of protection of a
commercial program
Anti-Virus Software (cont.)
Trend MicroSystems PC-CillinTop-rated choiceVery effective
Norton Anti-VirusNot my favorite – I’ve had problems
McAfee Anti-Virus
Anti-Virus Software (cont.)
Wizards handle installation seamlessly
Configure automatic email/file attachment scans
Need to upgrade virus signature subscription yearly if you don’t upgrade program
Anti-Malware Software
Malware is catchall term for spyware and adware-type programs
AdwareSoftware that, without your consent, tracks
and reports your web usage to another entity without reporting personally identifying information
Anti-Malware Software (cont.)
SpywareSoftware whose purpose is to collect
personally identifying demographic and usage information from your computer, usually for advertising purposes
Software that 'sneaks' onto the system or performs other activities hidden to the user.
--http://cexx.org
Anti-Malware Software
No one program today catches all spyware – multiple programs neededSpyBot Search and Destroy
http://www.safer-networking.orgAdAware
http://www.lavasoft.comTrend MicroSystems Anti-Spyware
Web-based scanhttp://www.trendmicro.com
Software Alternatives
Microsoft products are favorite targets of crackersWidespread use (80%+ of PCs use these)Easily exploitable security holesParticularly vulnerable
Internet Explorer – web browserOutlook – email client
Software Alternatives (cont.)
Web BrowsersMozilla FirefoxOpera
Email ClientsMozilla ThunderbirdEudora
Office SoftwareOpenOffice
Alternatives to Internet Explorer
Mozilla Firefox
Tutorial: http://opensourcearticles.com/articles/firefox_15/english/part_01
Opera
Alternatives to Outlook
Email is most vulnerable feature of Outlook
Most alternatives only deal with emailScheduling, memo, other features not
provided
Eudora
Download from http://www.eudora.com
Available in free, ad-supported, or paid versions
Supports multiple email accounts, folders, junk email filtering
Mozilla Thunderbird
Imports existing email and contact information
Similar look & feel to Outlook
Handles multiple email accounts
Provides adaptive junk email filtering
Automatically blocks scriptsDeters spread of viruses
Mozilla Thunderbird (cont.)
Download from http://www.mozilla.com/
Excellent tutorial: http://opensourcearticles.com/articles/thunderbird_15/english/part_01
Mozilla Thunderbird (cont.)
InstallationWizard handles all work
ConfigurationSet up account(s) Import existing email/contact infoSet up spam filtering
Office Software
Open OfficeAlternative to Microsoft OfficeMostly, but not fully, compatible
Available from http://www.openoffice.org/
Other Software
Windows Media PlayerPotential for privacy invasion through
“supercookie”Disable with following step:
Tools->Options->PlayerUncheck box beside “Allow Internet sites to
uniquely identify your Player.”
Other Software (cont.)
Windows MessengerAllows pop-ups without an active browserNot to be confused with MSN Messenger!To stop, disable the service
Start->Run, type services.msc & click OKDouble-click the Messenger entryChoose StopChoose Disabled from the StartUpType list
Using Your Computer Securely
Monitor your computer’s behavior
Schedule maintenance tasks
Use hard-to-break passwords
Protect your data files
Take precautions with Internet data
Be extra careful with wireless networks
Monitor Your Computer
Watch for unusual activity
Signs of problems:Excessive hard disk accessSlow operationPop-up windows
Schedule Maintenance Tasks
Running tasks automatically ensures they are actually run!Many programs let you schedule them from the program itselfOther programs can be scheduled from Control PanelStart->Settings->Control Panel->
Scheduled Tasks
Schedule Maintenance Tasks
Recommendations:Full virus scan weeklyFull spyware scan with Spybot weeklyFull spyware scan with Ad-Aware weeklyAutomatic updates for softwareAutomatic updates of signature files weekly
for all programs using them
Password Choices
Choose passwords that areCombinations of letters, numbers, and
symbolsDo not contain any identifying data
Birth datesFamily members’ names/variations
Are at least eight to ten characters long
Password Security
Do not write down passwords or PINsEspecially don’t keep written passwords or
PINs with the item using them!
Do NOT give ANYONE your password or PIN
Changing Passwords
Do not use the same password for everything
Change your passwords regularly
However, it’s better to use a “good” password badly than to use “bad” passwords well
Data File Protection
Do not make sensitive files accessible through networkDisable file sharing If files must be shared, password-protect
them
Data File Protection (cont.)
Simply deleting a file is not enough!Files remain in the Recycle/Trash bin after
deletionRecovery from here is simpleMust either specifically delete files from
Recycle Bin or empty Recycle Bin
Precautions with Internet Data
Use secure browsers and sites
Clear your data after use, especially from public computers
Browser Security
Make sure you are using Secure Socket technology if sending personal information to a web site Indicated by
Lock icon at bottom of browser windowhttps:// prefix on site URL (not http://)
Smart Use of Cookies
Most users will need to use cookiesMany legitimate Internet uses require them
Browsers should be set toReject third-party cookiesRestrict first-party cookies
Smart Use of Cookies
Internet ExplorerTools->Internet Options->Privacy
Select Advanced ButtonCheck Override Automatic Cookie HandlingSelect Block Third-Party cookies
Mozilla FirefoxTools->Options->Privacy->Cookies
Allow only originating site to set cookies
Browser History
Internet ExplorerHistory button on ToolbarSelect all items in window and delete
Mozilla FirefoxTools->Options->Privacy
Click on Clear button beside history
Removing Temp Files
Make hidden files visibleStart -> Programs -> Accessories ->
Windows Explorer.Tools -> Folder Options-> View -> Show
Hidden Files and Folders, Apply
Navigate in the left-hand pane to C:\Documents and Settings\%your username%\Local Settings.
Removing Temp Files (cont.)
Delete all contents in the following folders:TempTemporary Internet Files Content.IE5 (subfolder to Temporary
Internet Files) Note: Windows will warn you that you are trying to delete system files. This is okay, so click Yes.
Wireless Networking Concerns
Wireless network connections are inherently insecure
Broadcast, not point to pointAnyone within range can intercept signalOnce signal is intercepted, anyone can
view dataMany tools exist to do this
Wireless Networking Concerns (cont.)
Even encrypted transmissions are vulnerableAny currently used encryption scheme can
be brokenMost common scheme can be broken by a
middle-schooler in about 15 minutes!
Wireless Networking Concerns (cont.)
Don’t enable file sharing on computers using wireless network connections
Don’t transmit sensitive data OF ANY TYPE over a wireless networkDon’t shopDon’t bank online
In Closing
Suggestions and recommendations are for the normal user
The truly paranoid do need additional precautionsBut these require much more knowledge
Once your security is set up, maintenance will not be much effort
Thank you for attending!
This presentation is available online athttp://www.gpc.edu/~jbenson/presentations/security.ppt
Contact information: Julia Benson-Slaughter
Associate Professor of Computer ScienceDepartment of Business/Computer ScienceGeorgia Perimeter College2101 Womack RoadDunwoody, GA 30338