"Khar Shian Campus: Safe Computing"

1—Introduction

Welcome to Safe Computing! We live in a digital age. The internet is the tape that binds the world together. Computers have become far more than a hobby. They are now used in almost every aspect of business, education, and professional areas. As the number of computer users has increased, so has the number of vulnerabilities and exploits. People known as hackers, crackers, or phishers use technology to hijack computers and do damage to user data, or steal it. Therefore, it is important to remain informed and set up proper defenses on your computer. Whether it is for your personal laptop or datapad, the information in this course is designed to help keep you safe!

2—Firewalls

A firewall is just that: a barrier to keep unwanted visitors out. Computers pass data through what are called ports, openings in which data can be sent and received. Without a firewall, many ports remain open and vulnerable to being used by a hacker to pass data you do not want into your PC. A firewall essentially closes those ports and hides them. In addition, it monitors the data going through the open ports and ensures that it is not harmful.

More recently, firewalls also monitors activity between programs on the computer. If, for example, an IRC program attempts to open Internet Explorer, the firewall will display a warning to the user:


Click to enlarge.
And ask whether or not the user will allow that to happen. This is called program hijacking when, say, a virus attempts to open a program to do something harmful. Here are some firewalls:

Kerio Personal Firewall
Sygate Personal Firewall
ZoneAlarm

Until recently, these free versions were sufficient to protect computers, but they are not guaranteed to solve or prevent all problems. The companies usually offer a Pro version of their software (which normally does a lot more) at a cost.

3—Anti-Virus

A computer virus is not unlike a virus that infects people. Like its bodily counterpart, a computer virus infects a program and inserts new instructions that cause the program to operate differently (usually something destructive). An anti-virus program scans files for such strings of code and tries to cleanse the file of the infection.

There are a few items that fit into the virus category:

• Virus: Your standard computer virus.
• Worm: Proliferated mostly through the Internet, a worm (usually) uses either a website or e-mail to sneak into your computer and deliver a payload (usually a virus).
• Trojan: A virus with the intention of stealing personal information from the user, or opening a backdoor into the computer for a hacker to get into.

Viruses, in general, can do a variety of things to a computer. A virus can do something as trivial as make a message box appear with an insulting message or something as deadly as wiping your hard drive. Unless you want to have your computer open to attacks, make sure you have an up to date anti-virus program! Unfortunately, unlike firewalls, some of the best anti-virus programs must be purchased to reap the benefits of consistent updates and large virus databases. Some of the more prominent ones are:

• AVG Free (http://free.grisoft.com/doc/2/lng/us/tpl/v5)
• Eset’s NOD32 (http://www.nod32.com)
• McAfee (http://www.mcafee.com)
• Symantec’s Norton Anti-Virus (http://www.symantec.com)
• Panda Anti-Virus (http://www.pandasoftware.com)
• Kaspersky’s Anti-Virus (http://www.kaspersky.com)

4—Spyware/Adware

The term ‘pop-up’ has become a household item in the past year. In actuality, a pop-up is nothing more than a small line of JavaScript that creates a new window. However, advertisers have begun to abuse that functionality by inundating programs and websites with many pop-ups. Luckily, many Internet browser companies (like Microsoft, Opera, and Mozilla) have begun to build pop-up blockers into their browsers. Still, there are other pop-up blocking alternatives such as the Google Toolbar.

Spyware is software that monitors what programs the user may run, the websites the user visits, and other kinds of information and sends it without the user’s knowledge to a company. Many programs, especially file sharing programs like Kazaa and the more modern Torrent programs (like utorrent), install spyware programs (Gator, for example) when they are installed. Spyware can also be installed through websites, either through a plug-in such as an ActiveX control or as a tracking cookie.

Programs like SpyBot Search and Destroy (http://www.security.kolla.de) and Ad-Aware (http://www.lavasoft.com) can catch these harmful programs and subsequently remove them from your system. However, spyware detection functionality is fast being added to many anti-virus programs.

Other *-ware terms you should know:

• Adware: A program that, while usually free, has rotating advertisements within it to generate income.
• Shareware/Trialware: A fully-functioning program that ceases to work after (usually) 30 days.
• Freeware: A program that is completely free to use.
• Ransomware: Refers to a program (usually a virus) that encrypts files and then informs the user he/she must pay a certain amount to the hacker to get the password to decode the files.
• Malware: Programs created with the intention to harm a computer in some way.
• Open Source: Like freeware, but the actual code for the program is free and anyone can modify it and make their own program

5—Keeping Your PC Clean and Up-to-Date

Just about everyone who’s used computers for a while had heard the terms “defrag,” “scan disk,” and “cleaning the internet cache.” But what do they mean, and why do you have to do them?

Think of your computer’s hard drive as a large filing cabinet. As files are taken out and put back in, they’ll probably get out of order, and some may go missing. With a computer, this is called fragmenting. So, when you defrag a computer, it’s like putting all the files in the filing cabinet back into their proper place.

ScanDisk is a program that comes with the Windows OS. This program checks the integrity of the actual hard disk. Using the file cabinet analogy, it would be like examining the exterior of the cabinet for dents, making sure that the file cabinet isn’t about to fall apart. ScanDisk checks the integrity of files, as well as the physical hard drive.

Cleaning your computer is just as important as periodically cleaning your room. Delete unused files and programs regularly! Two very important items to clean out are the Internet Cache and Temp folders on your computer. To do so:

• Open Internet Explorer.
• Click on “Tools,” and then “Internet Options.”
• On the “General” tab, simply click “Delete Files” under “Temporary Internet Files.”
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You will also want to delete your cookies every so often as well. To clean out the Temp folder:

• Open Internet Explorer.
• In the Address bar, type %temp%.
• This will bring you into the Temp folder. Simply select all the files and then hit the Delete key.
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There are several (free) utilities that can accomplish these tasks, and in many cases you can automate them so you don’t have to worry about running them yourself. Windows comes with its own defragmenting and ScanDisk software, which are usually fine at getting the job done. If you need something a little better, here are some recommendations:

• Diskeeper (http://www.executive.com): while you have to pay for this application, it actually defragments your computer periodically as you use it. It can also be set to defrag and ScanDisk at boot time, among other things.
• Crap Cleaner (http://www.ccleaner.com/): A freeware tool that cleans out not only your Internet cache, but many other programs as well including the Windows Registry!
• Windows Washer (http://www.webroot.com/): Similar to Crap Cleaner, but you must pay for this program after an initial trial period.

Keeping your computer up to date with the latest patches and programs is also very important to defeat vulnerabilities and security holes. On a Windows PC, ensuring that Automatic Updates is set to on is the easiest way to receive updates to Windows.

In order to set Automatic Updates to on, do the following:

• Click “Start.”
• Go to the Control Panel.
• For Windows XP SP2, double click on “Security Center” or “Automatic Updates.”
• For Windows 2000 or Windows XP SP1 or RTM, double-click on “Automatic Updates” OR right-click on “My Computer” and select the “Automatic Updates” tab.
• For Windows ME, you will first need to download an update to allow for Automatic Updates. After doing so, go to the Control Panel and double-click on “Automatic Updates.”
• Set Automatic Updates to download the updates automatically.
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• Note: Automatic Updates only downloads critical system updates. To download other optional updates, you must go to the Microsoft Update website (http://microsoft.update.com).

Most importantly, keep yourself informed! There are many websites you can check into periodically to check for program updates or just bulletins regarding the technology industry. A couple websites to watch:

• BetaNews (http://www.betanews.com): Features latest betas of tons of software, as well as updated (daily) news features.
• Cnet (http://www.cnet.com): The Internet’s premiere technology website. It has reviews of software, hardware, and almost everything in between.
• Microsoft Security Bulletin (http://www.microsoft.com/security/): Microsoft’s own website on the latest vulnerabilities in Windows and other Microsoft products.
• PC World (http://www.pcworld.com): PC World Magazine is a reliable source for computer information. Their downloads section offers a wide variety of programs, and has a Privacy and Security section (there are many other sections with useful/fun programs). PC World links you to free, trial, pay, and shareware programs, all of which are perfectly legitimate.

6—Macintosh OS X

Maintenance on Macintosh desktops or Macbooks tends to be simplier than on a PC. More modern Macs come with built-in anti-virus software, so unless you want extra protection you don't have to worry about buying and upgrading any. Software updates run through a program that checks for updates for everything on your computer, from programs like iTunes to the operating system itself, and you can set the computer to automatically check for updates or you can do it manually. Automatic updates, along with most other system settings, can be found in the System Preferences. There are plenty of third-party Mac OS X applications out there that you can use for protection, though. All you have to do is Google them and check around.

7—Conclusion

What I have provided here is simply a succinct overview of a few key things and programs you can run to help improve your computer’s safety and performance. When your computer has a reliable firewall, anti-virus, and you take the time to clean out your PC every now and again your computer will thank you. The URLs and programs I have provided are by no means an exclusive list. Hop on to your favorite search engine and find some for yourself!