8: Basic SecurityNetworking for Home & Small Business

What’s Ahead…• Networking Threats

• Methods of Attack

• Security Policy

• Using Firewalls

Networking

Threats

Network Intrusion• Attacks can be

devastating– Cost money, time, theft of

files, etc

• HACKERS– Intruders who gain

access by modifying software or exploiting software vulnerabilities

4 Threats from Hacker• Information theft

• Identity theft

• Data loss / manipulation

• Disruption of service

4 Threats from the Hacker• Stealing Confidential Info

– Credit card #’s– Private Company info such as a project in

development– Could be sold

4 Threats from the Hacker• Destroy or Alter Records

– Send a virus that reformats HD– Changing your grades– Change store prices

4 Threats from the Hacker• Identity Theft

– Stealing info to take on identity– Applying for credit cards & buying stuff– Obtain DL’s

4 Threats from the Hacker• Disrupting Service

– Preventing user from accessing services such as Internet

Activity

Where’d He Come From?• External Threat

– Outside attacker– Internet or Wireless

Where’d He Come From?• Internal Threat

– Has authorized access• Knows people & network• Knows what info is valuable

– OR someone may have just picked up a virus

• According to the FBI, internal access and misuse of computers systems account for approximately 70% of reported incidents of security breaches.

Social Engineering• Easiest way to gain access…• Deceiving internal users into performing

actions or revealing confidential info– Takes advantage of them– Usually don’t meet them face-to-face

Fight Intrusion

• http://www.us-cert.gov/reading_room/before_you_plug_in.html

• http://www.us-cert.gov/reading_room/distributable.html

• Example 1

• Example 2

3 Types of Social Engineering• Pretexting, Phishing, and Vishing

Phishing

Review

Let’s Try This…• Cyber Security Awareness Quiz

Methods of

Attack

Other Attacks• Viruses, Worms and Trojan horses

– Malicious software put on hosts– Damage system, destroy data, deny access– They can forward data to thieves– Can replicate to other hosts

3 Evil Things• Viruses, Worms and Trojan horses

– Go to 8.2.1.2

Simplified

Virus Attaches to a program

Can reproduce Causes havoc!

Worm Self-replicating Sends copies of itself to other comp. w/ security holes

Cause harm to network; ties up bandwidth

Trojan Horse

Computer program disguised

Does damage when run

Can’t replicate

Let’s See…• GCIT

• Who wants to play…– ID Theft Faceoff?– Invasion of the Wireless Hackers?– Phishing Scams?

• Quiz Time for all!– http://www.sonicwall.com/phishing/

Activity• Virus, Worm or Trojan Horse???

Just Being Evil!• Sometimes the goal is to shut a network

down & disrupt the organization– Can cost a business lots of money!!

Denial of Service (DoS)• In general, DoS attacks seek to:

– Flood a system or network with traffic to prevent legitimate network traffic from flowing

– Disrupt connections between a client and server to prevent access to a service

– Some are not used much anymore, but can be

• SYN flooding• Ping of Death

DoS- SYN Flooding

DoS- Ping of Death!• Sending SO MANY LARGE pings, the

server can’t respond to anyone else!

DDoS• DDoS

– Attack by multiple systems infected with DDoS code

– Sends useless data to server– Overwhelms system & it crashes

Brute Force• Fast computer used to guess passwords or

decipher encryption code• Brute force attacks can cause a denial of

service due to excessive traffic to a specific resource or by locking out user accounts

• Try 8.2.2.3

Review• Name 3 types of social engineering.

– Pretexting, Phishing, Vishing• How are you targeted in a pretexting

attack?– Over the phone

• You click on a pop-up window to claim a “prize.” A program was installed w/out you knowing & now an attacker has access to your system. What is this called?– Trojan Horse

Review• Which attack doesn’t need activation and

copies itself across the network?– Worm

• A server is busy responding to a SYN with an invalid source IP address. What’s the attack?– SYN Flooding

Other Threats• Not all threats do damage

– Some collect info

• Collecting Info/Invading Privacy– Spyware– Tracking Cookies– Adware– Pop-ups

Spyware• Program that gathers personal

info w/out your permission– Info sent to advertisers

• Usually installed unknowingly– Downloaded, installing a

program, click on pop-up• Can slow computer down or

make settings changes• Can be difficult to remove

Toolbars

Keyloggers

Bundled Software

Tracking Cookies• Form of spyware

– Not always bad• Records info about user

when they visit web sites– Allows personalization– Many sites require them

Adware• Form of spyware• Records info about user when they visit

web sites• For advertising purposes

– Pop-ups & pop-ups of ads

Pop-Ups (and Pop-Unders)• Adware EXCEPT doesn’t collect any info

• Pop-ups– Open in front of the current browser window

• Pop-unders– Open behind the current browser window

What’s This?

Spam• Unwanted bulk mail from advertisers• Spammer sends

– Often sent through unsecured servers– Can take control of computers– Then sent from that computer to others

• On average, how many spam emails are sent to a person per year?– 3000

Review• You visit a web site and see this annoying

advertising tactic that appears in a new window. What is it?– Pop-up

• This type of advertising is sent to many, many people. The advertiser uses no marketing scheme.– Spam

• This form of spyware is not always bad & can be used for personalization of a site.– Cookies

Security

Policy

Security Measures• You can’t eliminate security breaches

– You can minimize the risks

• Policy• Procedures• Tools & Applications

Security Policy• Formal statement of rules when using tech

– Acceptable use policy– Detailed handbook

• What should be included?

Activity• Let’s review some policies…

• GCIT• Klondike Middle School• Clearview High School

More Security Procedures• The procedures help implement the policies• Some of the security tools and applications

used in securing a network include:

Rut Roh!• Computer starts acting abnormally• Program does not respond to mouse and

keystrokes.• Programs starting or shutting down on their own. • Email program begins sending out large

quantities of email• CPU usage is very high • There are unidentifiable, or a large number of,

processes running. • Computer slows down significantly or crashes

Anti-Virus Software• Preventive & Reactive tool• Features

– Email checker– Dynamic Scanning (checks files when

accessed)– Scheduled scans– Auto update

• When a virus is known, they will update it

Anti-Spam• Spam sends unwanted emails

– Code takes over PC to send more• The software ID’s it & places it in junk

folder or deletes it• On PC or on email server

– ISP may have a spam filter

Other ways to prevent spam• Keep anti-virus up to date• Don’t forward suspect emails• Ignore the virus warning email• Report spam to admin to be blocked• Don’t open attachment from people you

don’t know

Anti-Spyware• Spyware & Adware cause virus-like

symptoms– Use computer resources

• This software can detect & delete them

• Pop-Up Blockers

Activity

Review• This policy says what you can & can’t do

on a network or computer.– Acceptable use policy

• T or F. A-V companies like McAfee can protect you against every known virus & future viruses.– False

• T or F. It is possible for legitimate emails to be marked as spam.– True

Review• T or F. With A-V & anti-spyware installed,

you need not worry about opening email attachments. You are completely safe!– False…why?

• Other than on your PC, Google’s Gmail servers have this security software installed.– Spam Filter

Firewalls

What’s a firewall?• Controls traffic between networks & helps prevent

unauthorized access– Permits or denies data

4 Types of Firewalls

Firewall Decisions Based On• Packet Filtering

– Based on IP or MAC addresses

• Application / Web Site Filtering– Based on the application.– Websites can be blocked by URL or keywords

• Stateful Packet Inspection (SPI) – Must be responses from internal host– DoS saver

Firewall Placement & DMZ

GCIT & DMZ• Web Server (has GCIT web site)• Email Server (allows outside access)• File Server (allows file access from outside)• DRAW DMZ

Firewall & DMZ at home/ Port Forwarding/ Wireless AP internal

• Let’s say you have a web server• It needs to handle web request while you

still protect you internal network• Create a DMZ with the Linksys

Lab 8.4.2.4• DMZ Setup Lab

– Set up DMZ– Set up port forwarding– You can even set up time/day access (will not

do in the lab)

Review• Which type of firewall…

– Is dedicated hardware & the best?• Appliance

– Is on a single computer?• Personal

• What is an area that is accessible to internal PC’s & outside PC’s?– DMZ

• What 3 security measures can be set up for a server on your network that needs public access?– DMZ, port forward, time/day

Review• How many firewalls would a big business use?

– Two firewalls• What of these can you setup in a wireless access

point for security? – Popup stopper, Change the default IP address, Update

the antivirus software, Tighten the cable between the AP and PC• Change the AP default IP from 192.168.1.1 to 192.168.x.x

• Which process allows firewall entrance into the network ONLY IF it was requested from an internal PC?– SPI

Is Your Network Vulnerable?• Tools to help identify where attacks can

occur– Number of hosts on a network– The services hosts are offering– The OS and update versions on hosts– Packet filters and firewalls in use

• Lab 8.4.3.2?– Vulnerability Analysis

Lab 8.4.3.2• Vulnerability Analysis

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8: Basic SecurityNetworking for Home & Small Business