Wifi Hacking Part 1: Breaking WEP keys

In a previous post, I mentioned that I would provide tutorials for some of the things I am learning to do.  It has been said that one of the best ways to learn something is to teach it.  Today I will demonstrate how to crack a WEP key for the purpose of gaining access to a WEP protected wireless network.

Note:  This tutorial is intended for educational purposes only.  I do not encourage nor endorse the use of these tools for malicious or illegal use.  Do not go steal your neighbors wifi!

To perform this the operations detailed in this tutorial you will need the following:

• A compatible wireless adapter.  I use the TP-Link TL-WN321G.  It's only ten bucks and works out-of-the-box with Linux.
• Aircrack-ng suite--  This comes preinstalled on BackTrack 4, or can be acquired on Ubuntu by typing sudo apt-get install aircrack-ng
• A wireless network to perform these "attacks" on i.e. one that you own or have permission to use.
• GNU Macchanger-- also preinstalled on BT4 or can be aquired on ubuntu by typing sudo apt-get install macchanger
• A computer running some flavor of Linux.  Either the aforementioned Backtrack or ubuntu will work just fine.  Others will also work, but those are the two I have used.

The Most Powerful Security Tool

Judging from the title of this post, one may presume that I am going to recommend some great new anti-virus software, firewall, or password manager. But that presumption would be incorrect. What most folks do not realize is that the best security tool available is free and can be used by anyone. I am talking about knowledge. The best way to protect yourself and your data is to educate yourself about the tactics used by attackers.

Too many people believe that they are secure just because they have a piece of software installed that said "Protects from viruses and hackers" on the back or the box. The problem here is, that most of the real cyber-security threats today do not exploit computer code, but rather exploit a user's lack of knowledge. It is these social engineering threats that one must be aware of. Scams in the form of phishing emails are the most prominent example of this. Do not click links in emails from people you don't know. Do not click on those "videos" that a "friend" posts on your Facebook wall asking you to download a special video player. I think you get the idea. When in doubt, do not click.

Another extremely dangerous threat and all-too-common threat to the user, is the user itself. Too many times do people use the same password for every website that they create an account at, and too often is it some easily guessable piece of information, such as a pet's name, phone number, or birthday. Creating good strong passwords is an excellent place to start for anyone looking to increase security. For example, anyone who has had their Facebook, YouTube, Myspace, or email accounts hacked, probably used a poor password made of readily available personal information. A good rule of thumb is that any password should be at least eight characters long, and should contain at least one number, punctuation and uppercase letter. Skimping on password strength is the easiest and most surefire way to get yourself "hacked."

Please take this advice into consideration next time you get a strange looking email, or need to create a new online account. Don't expect some piece of software or some company to save your cyber-bacon. Just remember that it is up to you to make sure your digital assets are protected.

Hacking to Learn

These days the word hacker carries a negative connotation for most people. Whether its a misconception caused by the mainstream media, or an individual's own experience with data theft, most non-geeks think of hackers as being some kind of criminals. While it may be true that there are some hackers out there that use their skills for personal gain, most geeks like myself see hacking in a different way.

For the non-criminal geeks, hacking is something to be taken as a challenge to prove one's skills. Knowing how to crack a WEP key for someone's wireless network can be used for both good and bad. Of course you could leech Wi-Fi from your neighbors, but the opposite argument also applies. You could instead use your skills to show your neighbors that they have a security issue, and that you can fix it for them. That is the essence of offensive security. In order to be able to defend a system from penetration, one must know what that system's vulnerabilities are. Consider this. Most people believe that their houses are secure, but if locked out of their own houses, could probably find a way in. The same principle applies to network security.

I have taken it upon myself to learn this other side of security, and have been coming along with it within the last few weeks. I have already learned how to crack WEP using aircrack-ng on Linux and am currently tackling WPA cracking. If you are a geek and have an interest in learning these tools, I encourage you to use them for good. Backtrack 4 is the best way to start, as it contains almost every cracking, hacking, and penetration tool one would ever need. Please don't hack anyone's networks without permission, or sniff passwords at a coffee shop, because both of these could land you some jail time.

I will write follow-up articles, and possibly tutorials on how to use these tools, so please continue to follow my blog if you are interested.