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