1. Internet Security
CIT 1100
Chapter4

2. Local Security In this chapter you will learn how to:
Discuss different types of malicious software
Protect against viruses
Discuss browser configuration and firewalls

3. Malicious Software
The beauty of the Internet is the ease of accessing resources, unfortunately this connection runs both ways, allowing people potential access your computer
Malware consists of computer programs designed to break into computers
The programs are written by people known as hackers
Hacking refers to the circumvention of computer security, which malware is designed to do
The most common types of malware are grayware, spam, viruses, Trojan horses, and worms
You need to understand the different types of malware so you can combat them

4. Grayware
Programs that intrude into your computing experience but don't actually do any damage to your systems or data is referred to as grayware
On most systems, the Web browser is the most often used piece of software. Over the years, Web sites have come up clever ways to force you to see their advertising
There are basically three grayware types:
Pop-Ups
Spyware
Adware

5. Pop-Ups
Spyware can fire up pop-up windows of competing products on the Website you're currently viewing
Getting rid of pop-ups is rather tricky, pop-up browser windows don't look like browser windows at all, they have no menu bar, button bar, or address window, yet they are separate browser windows
HTML coding allow Web sites and advertising designers to remove the usual navi­gation aids from a browser window so that all you're left with is the content
Some pop-up browser windows are deliberately designed to mimic similar pop-up alerts from the Windows OS

6. Pop-Ups
The first thing to know when dealing with pop-ups is how to close them without clicking them
Pop-ups remove all navigation aids, many are configured to appear on your monitor screen placing the browser window's exit button outside of your visible area
Some hide behind the active browser window waiting in the background
The fix is to always use alternate means to close pop-up windows:
Right-Click the browser's icon in the taskbar area to generate a pop-up menu of your own.  Select Close
ALT-TAB to bring the browser window in question to the forefront and then press ALT-F4 to close it.
Web browsers have features to prevent pop-up ads in the first place, these types of applications are sometimes too thorough, they tend to prevent all new browser windows from opening, even those you want to view

7. Spyware
Some types of spyware go considerably beyond the level of simple intrusion
They can use your computer's resources to run distributed computing applications which can:
Capture your keystrokes to steal passwords
Reconfigure your dial-up settings to use a different phone number at a much higher connection charge
Use your Internet connection and address contacts list to propagate itself to other computers

8. Spyware
Spyware can seriously impact your PC's performance and cause prob­lems with your Internet connection
Downloading and installing something unknown to the user is the common way Spyware is introduced system
Spyware authors bundle the virus into other programs and utilities that look legitimate and are give away free
Instead of offering you some sort of free utility, some use fear tactics to try to trick you into installing their software one popular method is to use pop-up browser windows disguised as Windows system warnings
Do not click anywhere inside the pop-up Use ALT-F4

9. Spyware
Spyware detection and removal software should be a part of every system and run regularly
Once downloaded and installed, spyware removal can be tricky
Windows includes Windows Defender for capturing and removing Spyware
Another piece of software available for free from Microsoft is Security Essentials which must be downloaded from MicroSoft

10. Spyware
Windows Defender

11. Microsoft security essentials

13. Spam
from a source that's not a friend, or colleague, and that you didn't ask for, can create huge problems
Unsolicited , called spam, accounts for a huge percentage of Internet traffic
Spam comes in many forms from legitimate businesses try­ing to sell you products to scammers
There are several options to cope with the flood of spam:
Never post your address on the Internet
Filters and filtering software can block spam at your mail server and at your com­puter
You can set most programs to block from specific people, or by subject line or keywords

14. Viruses
A virus is a piece of malicious software that gets passed from computer to computer
It is designed to attach itself to a program on your computer
Whenever you use the infected program, the virus goes into action and does whatever it was designed to do
Viruses can also be used to steal information or send spam s to everyone in your address book

15. Trojans
Trojans are freestanding programs that do something other than what the person who runs the program thinks they will do
A program that a person thinks is an antivirus program but is actually a virus is a good example
Trojans can be quite sophisticated possibly disguising itself as a game that is also causing system damage

16. Worms
Like a Trojan a Worm is a complete program that travels from machine to ma­chine, usually through computer networks
Worms are designed to take advantage of security problems in operating systems and install themselves on vulnerable ma­chines
They replicate themselves over and over on infected networks and can create so much activity that they overload the network by consuming bandwidth

17. Worms To protect yourself and your data against security threats:
Always use the latest antivirus software especially if you con­nect to the Internet via an always-on broadband connection
Use a firewall, as part of your network hardware or by means of a software program
Worms infect systems through security flaws in operating systems, make sure you have the latest security patches installed
A security patch is an addition, to patch a hole in the systems code
Microsoft Windows Update tool is handy for Windows users, as a sim­ple method to ensure that your version's security is up to date
A downside is not everyone remembers to run Windows Update Always set Windows Update to run automatically

18. Virus Prevention and Recovery
When you discover an in­fected system, you need to know how to stop the spread of the virus to other computers and fix the infected computers using an Anti-Virus program
An Anti-Virus program protects your PC in two ways:
Active seek-and-destroy mode
Passive sentry mode
In seek and destroy, the program actively scans the computer's files for viruses if it finds any, presents you with the available options for removing or disabling them
Antivirus programs can also operate as virus shields that passively monitor your computer's activity, checking for viruses only when certain events occur, such as a program executing or a file being downloaded

19. Virus Prevention and Recovery
Antivirus program uses a library of signatures to detect known viruses
The signature is the code pattern of a known virus, like its fingerprint
Antivirus program compares an executable file to its library of known signatures
A legitimate program could coinci­dentally hold a virus signature causing it to be flagged as a virus the antivirus program's creator provides a patch to prevent further false alarms

20. Preventing Viruses
Antivirus programs should include a virus shield that scans , downloads, running programs automatically
Scan PCs often for possible virus attacks
Know the source of software before you use it
Keep your antivirus program updated since new viruses appear daily, many programs will update themselves automatically
Periodically update the core antivirus software programming- called the engine- to employ the latest refinements the developers have included

21. Virus Recovery Tips
When the inevitable happens and a computer gets infected by a computer virus, you need to follow certain steps to prevent the problem from spreading
Try this five­ step process:
1. Recognize - a potential virus outbreak occurred
2. Quarantine -cut off- the infected computer from the network
3. Search and destroy - do a safe boot and run your antivirus software
4. Remediate - fix things the virus harmed
5. Educate – users on proper downloading, etc

22. Browser Configuration
If a Browser’s settings are configured improperly you may be open­ing yourself up to outside attacks
ActiveX and Java are programming languages that can be integrated into Web sites
They allow Web developers to make Web pages interactive, but they can also be used to compromise your browser and run malicious code
If an unfamiliar Web site asks to run ActiveX or Java code, don't do it
ActiveX and Java can be deactivated entirely in most browsers

23. Browser Configuration
A Cookie is a text file containing information about you used to authenticate you as a registered user of a web site which is stored in your browser
They’re used to keep track of the shopping basket you select to buy and allows sites to present different looks and content to different users
They track your access to Web sites, including what products you look at, even if you don't buy them
Some track your Internet activities and report back to its creator, which is often sold to advertisers so that they can target you with spam
Browsers can be configured to partially or completely block cookies

24. Plug-ins
Plug-ins are tiny pieces of software that can add functionality to a browser
They enable interactive and audio/visual content such as videos
If you visit a Web site and are prompted to install a third-party ap­plication or plug-in that you've never heard of, never install it
Well-known and reputable plug-ins such as Adobe's Flash or Microsoft's Silverlight are considered safe

25. Firewalls
Firewalls are hardware or software that protect an internal network from unauthorized access
Hardware firewalls use a number of methods to protect networks, such as hiding IP addresses and blocking TCP/IP ports, a small Linksys home router for example acts as an effective firewall
Many high end routers use access control lists (ACLs) that can filter by port number, IP address, or sev­eral other attributes
Windows XP and later come with an excellent software firewall called Windows Firewall
It is capable of perform port blocking, security log­ging, and more
You can access the Windows Firewall by opening the Windows Firewall applet in the Control Panel

26. Firewalls
From the Control Panel -