Wireless Worries!

Written by Kevin Ray

ireless computer networks have become very popular because they eliminate unsightly wires, and allow laptop computer users unfettered mobility. Unfortunately, Wireless Local Area Networks or WLANs have their share of downfalls; vulnerability to security breeches being the biggest. WLANS if set-up properly can be quite secure, but most WLANS in private homes are not. In this article you will learn a couple of steps that you can take to drastically reduce your WLAN’s vulnerability to the bad people in the world who want to take your money, or even worse, your identity.

WLANs are designed to provide uninterrupted service using radio frequencies. Due to a lack of space and expense, the antennas on wireless networking cards in the end computers are typically weak, and require a considerable amount of energy to be used by the transceiver to pick-up signals. The consequence of this is that not only can wireless packets be intercepted by a nearby adversary’s antiquated computer, but a determined user with a little money for a high quality antenna can pickup packets at a remarkable distance; perhaps hundreds of times the radius of a typical user.

Wardriving is a term used to describe how a hacker armed with a laptop and an 802.11 wireless LAN adapter travels via car, bus, subway train, or other form of mechanized transportation sniffing for WLANs. Wardriving was named after “wardialing” which was popularized in the Matthew Broderick movie, “War Games”.

When a laptop’s wireless adapter (NIC) is set to promiscuous mode, it will receive any packets within its range. The goal is to find vulnerable locations in order to access free Internet service or obtain illegal access to sensitive and private information that can be used for illegal profit.

Software for wardriving is easily acquired on the internet. Using a device that is capable of receiving an 802.11 signal, and that can locate itself on a map using GPS, combined with software that will log data from the moment that a network is detected; the hacker moves from place to place letting these devices do their job. Over time, the hacker compiles a database comprising the network name, signal strength, location, and IP/namespace in use.

Via Simple Network Management Protocol (SNMP), a hacker may even log packet samples and probe the access point for available data. With only 40,000 acquired packets there is a 50% chance of success. The success rate climbs to 95% with 85,000 packets.

A hacker may also use a technique called Warwalking which is the same as wardriving, but is commonly performed in public areas like malls, hotels, or city streets using shoe leather instead of the transportation methods listed.

Once identified, the vulnerable WLAN’s location may be marked with chalk on the sidewalk, curb, or building itself so that others can locate it easily. This is called surprisingly enough, warchaulking.

It is believed that cracking Wi-Fi security protocol can be accomplished with some PDAs or mobile phones if they are equipped with wireless LAN hardware.

If you are currently using Wired Equivalent Privacy (WEP) protocol, stop using it right now! It now takes just 3 seconds to extract a 104-bit WEP key from intercepted data using a 1.7GHz Pentium M processor. The necessary data can be captured in less than a minute, and the attack requires so little computing power that it could even be performed in real time by someone walking by your house. If your network supports Wi-Fi Protected Access (WPA) or even better, WPA2, you should be using it instead of WEP.

If you are a business owner with old Wi-Fi hardware incapable of handling the latest WPA encryption, you can still protect your network in a cost-effective manner. For instance, point-of-sale systems can use a WEP Cloaking product recently released by AirDefense Inc. without having to upgrade every terminal or base station.

When you purchase a router (such as a Linksys, Belkin, Netgear, or D-Link to name a few) it comes with a factory default User ID and password to safeguard the router’s configuration panel. On the D-Link router for instance, the User ID is admin and the password is left blank. Since wireless hackers are familiar with the factory default settings of most routers, you should change the username/password combinations so they can’t get into the router and change its settings to suit their needs. Try using your router’s serial number. It’s unique, secure, and it’s usually found on the router itself. This is the most effective way to keep hackers out of your router. Unfortunately, this is the one step that most people skip and the hackers know it!

Wireless is wonderful, but it does have some serious downsides when setup incorrectly. There are several other steps that can be taken to increase security, and they should be implemented as well. If you are either unsure or uncomfortable with how to setup your router, you should find someone that isn’t, and that you trust to setup yours for you. Not only will it be more secure; it will also perform better!

This article provided by Kevin Ray of Custom Audio Video, LLC. Member CEDIA (Custom Electronic Design & Installation Association)