Whether or not you have secured your WLAN, with wireless networks, it’s not easy to predict the propagation of radio waves. Radio waves do not travel the same distance in every direction because obstacles such as walls, people, and land formations create
or weakening of the Wi-Fi radio signal. Because of this, many wireless networks are susceptible to attack by
I discuss placement of WLAN equipment and dealing with interference issues in Chapter 8.
Sniffers are available in many flavors, and most of them are free software down- loads for
I discuss weaknesses of Wi-Fi encryption in Chapter 10.
Sniffers are available for most operating systems, including handheld pocket PC devices, and even sniffing for WLANs using a keychain Wi-Fi seeker gadget (see Figure 5-6).
Figure 5-6: You can use devices like the Chrysalis WiFi Seeker to sniff out WLANs.
Although you have likely
Figure 5-7: Roaming for targets
Some of the sniffing software that an intruder uses can also capture passwords, unencrypted data, and even aid in cracking encrypted data. Because wireless communications are accessible to anyone connected to or within range of the WLAN, sniffing is the most effective technique in wireless attacks.
Typical sniffers are software programs that
To do this, sniffers place NICs into a monitoring state called
Wireless sniffers are powerful tools that you can use to audit and defend a WLAN as well as attack it. Because sniffing is usually a passive activity there is little you can do to detect and prevent it. Your best defense is to refer to Chapter 11 and follow the steps for securing your WLAN, and Chapter 10 for best practices regarding Wi-Fi encryption.
In this chapter, I reviewed some additional avenues of attack that crackers are likely to exploit, and steps that you can take to thwart them. These topics included:
Attacks against network
Exploiting OS vulnerabilities and known security issues
Keeping Windows patched
The secret to securing Simple File Sharing
Patching known security vulnerabilities
How wireless sniffing works
By following the recommendations in this chapter and throughout the book, you’ll be better prepared and you will be less likely to find yourself the victim of a wireless attack.