WiFi Scan

What is a WiFi Sniffer and Why You Should Care

Everything You Need to Know About WiFi Sniffers

WiFi networks have become the most predominant method for U.S. households with broadband access to connect to the Internet. According to ncta.com, 89% of the United States home broadband users employ a wireless router and use it to attach multiple devices to the net. WiFi hotspots have popped up all over the place and many mobile users make great use of them while sipping a coffee and monitoring their recent posts.

The aspect of wireless networks that is of most concern is the possibility that its security can be breached. An attack on a wireless network can be conducted from a distance, minimizing the potential for the perpetrator to be apprehended. One of the main tools used in WiFi attacks is called a WiFi sniffer. Let’s take a closer look at what exactly a wireless sniffer is and how it can impact your WiFi network.

What is a WiFi Sniffer?

A WiFi sniffer is a specific type of network analyzer or packet sniffer that is designed to work with wireless networks. WiFi sniffing can be accomplished with a dedicated piece of electronic equipment or a software application. Wireless network sniffing is akin to wiretapping a phone line, only without the court order that legalizes the activity.

There are valid and legal uses for a wireless sniffer tool to be used. An example is where a network administrator makes use of one to secure or monitor their network. Home users may employ a sniffer to better understand how their network operates. Unfortunately, a prime reason that WiFi sniffers are used by unscrupulous individuals is to attempt to collect information from, or gain access to, an unsecured network. A wireless sniffer allows someone to attack your network from a distance, making it hard to determine if there are attempts to compromise your data.

How Does a WiFi Sniffer Work?

WiFi sniffers come in two flavors: hardware and software. They perform the same tasks, though the software route may be more popular in most cases. You can obtain software WiFi sniffers for Windows, Mac, and mobile operating systems. In the case of a mobile device, you are in essence turning it into a hardware sniffer when using it with a sniffing application.

Hardware WiFi Sniffers

It does not take any special level of technical expertise to operate a hardware WiFi sniffer. Most devices are small and portable, able to easily fit in your pocket or laptop bag. You point the device in the direction where you believe a wireless network can be detected. You will be alerted by display lights when a wireless network is found within range of your device.

A WiFi sniffer for Android devices uses add-on tools and will offer a similar display when searching for networks. Quality hardware sniffers will be able to detect a wireless signal in spite of interference from Bluetooth devices, microwaves or cell phones.

Software WiFi Sniffers

There are many different software applications that serve the purpose of WiFi sniffing. You can download these tools for just about any operating system. Some of these tools have advanced features that allow you to do more than just locate the nearest wireless network.

Tools such as Wireshark and Network Miner serve as WiFi sniffers for the Windows platform. Users can download tools such as aircrack-ng or Zanti to perform WiFi sniffing on an Android device. There are many applications that enable WiFi sniffing on a Mac as well. We are going to use a free WiFi sniffer named KisMAC to see how you go about capturing WiFi traffic.

Capturing WiFi Traffic with a Wireless Network Sniffer

We are going to go through the steps required to capture WiFi traffic using the KisMAC software WiFi sniffer for the Mac. This free WiFi sniffer will run on your Mac OS X or macOS system. It is not a tool meant for the novice computer user, and troubleshooting will need to be done with some extensive web searches. That being said, here’s what you need to do.

Unfortunately, since KisMAC is an open source project there are limitations on its ability to function on newer MacBooks with the Airport Extreme Card. In these cases, you must obtain a USB WiFi card that will enable the tool to perform its sniffing activities.

  1. Download KisMAC and install it on your Mac.
  2. Go to Preferences -> Drivers and select the WiFi driver device to be used.
  3. Click on Add to use the selected driver.
  4. Click Start Scan and provide KisMAC with your administrator’s password.
  5. You will be presented with a list of wireless networks that are within range and the type of security they are using. In the case of networks with no security, you can directly join them. Networks protected by WEP or WPA will need a password to join.
  6. Click on the network you are interested in and you will start to accumulate data packets.

Once you are collecting data packets from the network you can attempt to crack the WEP or WPA security which will allow you to access the network. We leave those steps to be found with your own initiative.

Advantages and Issues Associated With Using a WiFi Sniffer

Obviously, some of the advantages of using a WiFi sniffer may not coincide with the privacy laws of your particular jurisdiction. It is legal to use a sniffer on your own network or to discover where wireless networks are located. Cracking passwords and gaining access to a network with the use of a sniffer is a crime and it is not our intention to lead you down that path.

WiFi sniffers definitely have valid uses in the business environment and can be an important tool in the hands of network administrators. These will normally be commercial-grade sniffers and often are implemented in hardware devices. Using this tool, admins can perform diagnostic tests on their network and troubleshoot problems. They can also help detect if the network has been subject to unauthorized access.

A powerful tool such as  WiFi sniffer in the wrong hands can cause serious trouble for your network and the data it transmits. A hacker can obtain your account information, steal passwords, read your emails, and track your online movements.  

Protect Your Data from WiFi Sniffers

Some simple steps can go a long way toward protecting your home network and your personal data when using unsecured WiFi at your local Starbucks. For home networks, ensure that your WiFi router is set to WPA encryption and choose a password that it at least 9 characters long. If you go up to 12 characters it is virtually impossible to crack your password in the hacker’s lifetime.

When accessing WiFi in locations that are not secured or where security is doubtful, follow these practices to safeguard your data. You need to assume that the nice guy with the laptop sitting across from you is there to steal your banking info. To thwart these kinds of attacks:

  • Refrain from doing any banking or financial activity while connected to an unsecured WiFi network.
  • Only use https encrypted websites.
  • Use a VPN to route your Internet activity through encrypted networks that cannot be compromised by hackers.

Now that you have seen what a WiFi sniffer can do and how it can impact your online activities, you should be better able to protect yourself and your data. The convenience of wireless networks can be enjoyed without risk if you take the necessary precautions. Make sure that you do.