Tue, Sep 22nd - 2:33PM
Network Security – The Real Vulnerabilities
Scenario: You work in a corporate environment in which you are, at least partially, responsible for network security. You have implemented a firewall, virus and spyware protection, and your computers are all up to date with patches and security fixes. You sit there and think about the lovely job you have done to make sure that you will not be hacked.
You have done, what most people think, are the major steps towards a secure network. This is partially correct. What about the other factors?
Have you thought about a social engineering attack? What about the users who use your network on a daily basis? Are you prepared in dealing with attacks by these people?
Believe it or not, the weakest link in your security plan is the people who use your network. For the most part, users are uneducated on the procedures to identify and neutralize a social engineering attack. What’s going to stop a user from finding a CD or DVD in the lunch room and taking it to their workstation and opening the files? This disk could contain a spreadsheet or word processor document that has a malicious macro embedded in it. The next thing you know, your network is compromised.
This problem exists particularly in an environment where a help desk staff reset passwords over the phone. There is nothing to stop a person intent on breaking into your network from calling the help desk, pretending to be an employee, and asking to have a password reset. Most organizations use a system to generate usernames, so it is not very difficult to figure them out.
Your organization should have strict policies in place to verify the identity of a user before a password reset can be done. One simple thing to do is to have the user go to the help desk in person. The other method, which works well if your offices are geographically far away, is to designate one contact in the office who can phone for a password reset. This way everyone who works on the help desk can recognize the voice of this person and know that he or she is who they say they are.
Why would an attacker go to your office or make a phone call to the help desk? Simple, it is usually the path of least resistance. There is no need to spend hours trying to break into an electronic system when the physical system is easier to exploit. The next time you see someone walk through the door behind you, and do not recognize them, stop and ask who they are and what they are there for. If you do this, and it happens to be someone who is not supposed to be there, most of the time he will get out as fast as possible. If the person is supposed to be there then he will most likely be able to produce the name of the person he is there to see.
I know you are saying that I am crazy, right? Well think of Kevin Mitnick. He is one of the most decorated hackers of all time. The US government thought he could whistle tones into a telephone and launch a nuclear attack. Most of his hacking was done through social engineering. Whether he did it through physical visits to offices or by making a phone call, he accomplished some of the greatest hacks to date. If you want to know more about him Google his name or read the two books he has written.
It’s beyond me why people try and dismiss these types of attacks. I guess some network engineers are just too proud of their network to admit that they could be breached so easily. Or is it the fact that people don’t feel they should be responsible for educating their employees? Most organizations don’t give their IT departments the jurisdiction to promote physical security. This is usually a problem for the building manager or facilities management. None the less, if you can educate your employees the slightest bit; you may be able to prevent a network breach from a physical or social engineering attack.
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Tue, Sep 22nd - 2:29PM
How Do Wireless Networks Work?
Wireless networks work using radio waves instead of wires to transmit data between computers. That's the simple version. If you're curious to know what's going on in more detail, then it's all explained in this article.
Ones and Zeros.
I'm sure you know that computers transmit data digitally, using binary: ones and zeros. This is a way of communicating that translates very well to radio waves, since the computer can transmit ones and zeros as different kinds of beep. These beeps are so fast that they're outside a human's hearing range -- radio waves that you can't hear are, in fact, all around you all the time. That doesn't stop a computer from using them, though.
Morse Code.
The way it works is a lot like Morse code. You probably already know that Morse code is a way of representing the alphabet so that it can be transmitted over radio using a dot (short beep) and a dash (long dash). It was used manually for years, and became a great way of getting information from one place to another with the invention of the telegraph. More importantly for this example, though, it is a binary system, just like a computer's ones and zeros.
You might think of wireless networking, then, as being like Morse code for computers. You plug a combined radio receiver and transmitter in, and the computer is able to send out its equivalent of dots and dashes (bits, in computer-speak) to get your data from one place to another.
All About Frequencies.
You might wonder, though, how the computer could possibly transmit enough bits to send and receive data at the speed it does. After all, there must be a limit on how much can be sent in a second before it just becomes useless nonsense, right? Well, yes, but the key to wireless networking is that it gets around this problem.
First of all, wireless transmissions are sent at very high frequencies, meaning that more data can be sent per second. Most wireless connections use a frequency of 2.4 gigahertz (2.4 billion cycles per second) -- a similar frequency to mobile phones and microwave ovens. As you might know, though, a frequency this high means that the wavelength must be very short, which is why wireless networking only works over a limited area.
In addition, wireless networks make use of a technique known as 'frequency hopping'. They use dozens of frequencies in the range they are given, and constantly switch between them. This makes wireless networks more immune to interference from other radio signals than they would be if they only transmitted on one frequency.
Access Points.
The final step is when it comes to all the computers on a network sharing Internet access. This is done using a special piece of wireless equipment called an access point. Access points are more expensive than wireless cards for one computer, as they contain radios that are capable of talking to around 100 computers at the same time, and sharing out access to the Internet between them. Dedicated access points are only really essential for larger networks, though -- if you only have a few computers, it is possible to use one of them as the access point, or you could just get a wireless router.
They Understand Each Other.
That's all well and good, then, but how does wireless equipment made by entirely different companies manage to work together when this is all so complicated? Well, the answer is that there are standards that all wireless devices follow. These standards are technically called the 802.11 standards, and are set by the IEEE (Institute of Electrical and Electronics Engineers). It is thanks to people sticking to their standards that wireless networking is so easy and cheap to use today.
You Don't Need to Worry.
If all this talk of frequencies has you a little worried, you don't need to be -- wireless networking hardware and software handles all of this automatically, without you needing to do a thing. Don't think that you're going to have to tell one wireless device what frequency another is using, because it's just not going to happen, alright? Wireless networking, for all its complicated workings, is really far more simple to use than you'd ever expect.
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