FactPlace

What You Need To Know About...

...Computer Security

1. The Basics
2. Viruses & Worms
3. Spyware
4. Hacking & Cracking
5. Identity Theft
6. Trojans
8. The People
9. Books & Gear
10. Useful Links

News: 9/6/2007 - Apple patches critical iTunes bug. Apple has released iTunes version 7.4 which, among other things, patches a security vulnerability that could allow a malicious music file to crash or take control of the user's machine.

The Basics

1.01 What is computer security?

Computer security is protecting your computer and, more importantly its data, from a variety of forces including malicious software, malicious individuals & even simple carelessness.

1.1 What is a "denial of service" attack?

A denial of service attack is an attack that is not intended to compromise or reveal any data or access any systems. It's sole purpose is to prevent you from accessing, or at least getting full benefit from, one or more of your systems. A typical example would be flooding your web server with traffic so that it can't respond to legitimate requests. It's the electronic equivalent of parking a car across your driveway so you can't get into your garage.

1.2. My password is "4f8Z%" That's unbreakable isn't it?

Well, no password is unbreakable when you tell people what it is. That aside, that password could be broken in less than half an hour. It's only 5 characters long and any brute force cracking software that takes a shot at that password would get it very quickly simply by trying every possible combination. To be secure a password should really be a pass PHRASE. Not only obscure, but LONG. "My 2 dogs are very cute!" is actually a good pass phrase (aside from the fact that I've just publicized it). It's about 20 characters long, is not a single English word, isn't easy to guess and contains mixed case characters, numbers and symbols. As long as you don't write it on a Post-It that pass phrase would be very secure and not hard to remember. I'm sure you can think of some on your own -- they don't have to be 20+ characters long, but 15+ is good.

1.3 Do I need a firewall for my home computer? Which one should I use?

Is it connected to the Internet? If so, yes. If you have a broadband connection (DSL or cable modem typically) check the Books and Gear section for a decent and inexpensive firewall solution for home.

Viruses & Worms

2.01 What is a virus?

A computer virus is a piece of code which infects files and replicates itself. Sometimes it is malicious and sometimes not; the replication is the key. Some of them have a payload which can be mischievous or destructive.

2.02 What is a worm?

A worm is a self-contained program that replicates itself. While a virus relies upon a host file of some kind to infect, a worm is its own program.

2.1 How do virus scanners work?

A virus scanner works by scanning code in memory or on hard drives. There are two basic kinds of virus scanners.

2.1.1 Signature Scanners

A signature scanner searches the contents of files looking for the unique signatures that identify a virus. Almost every piece of data or code, virus or otherwise has at least one unique string that can be used to find it. The weakness of signature scanners is that they will only catch viruses or worms that have already been identified, analyzed and whose signatures are included in the signature file your computer has. It is essential to keep your signature files up-to-date. Most signature scanners have updated signature files available for them on an almost daily basis.

Most signature scanners also have a way to automatically download updates on a regular schedule so that you don't have to remember to do it.

2.1.2 Heuristic Scanners

Heuristic scanners work by looking for viral behavior. They don't rely upon signatures, instead they monitor activity and look for suspicious activity. They are much better at catching new viruses because they don't have to wait for signatures to be updated and they tend to have fewer updates that you have to worry about. They are more unusual, however, and will only catch viruses who have behaviors that the scanner is watching for.

Spyware

3.01 What is Spyware?

Spyware is software that sends information, typically without the knowledge of the user, about the user or their activities to a third-party; typically via the Internet. Sometimes it's as simple as monitoring a user's web usage and sending that information to a company for marketing or tracking purposes. Sometimes it's more sinister -- collecting personal information like passwords or credit card information and sending that to a criminal.

Hacking & Cracking

4.1 What is a hacker? What is a cracker?

A hacker is somebody who investigates systems to learn the inner working of those systems. A cracker is somebody who attacks systems with malicious intent. (or a wafer often enjoyed with soup) Over the years, thanks in part to the media, the hacker term has been corrupted to be a bad thing.

4.1.1 Are hackers criminals?

Not all of them, no. Many of them are just folks who enjoy finding out how things work and have no criminal intent and do no harm.

4.1.2 What is a "White Hat?" What's a "Black Hat?"

A "white hat" is a hacker who uses his powers for good and not evil. Typically they are employed by security companies or other organizations to help protect them from....well, "black hats" (hackers who may have nefarious motives).

4.2 What is a "Pen Test?"

Pen test is short for "Penetration Test" which basically means trying to penetrate a system to discover weaknesses in its defenses.

Identity Theft

5.1 Shredders

If you don't have a home shredder you should. They are not especially expensive, less than $40 for a basic one. You should get in the habit of shredding anything with personal information on it that you were planning to discard. One prime example are those credit card offers you receive. Somebody could fish one of those out of the wastebasket, change the address, and send it in to get a credit card in your name.