What is Wireless Sniffing?

Robert Grimmick

Wireless sniffing is the practice of eavesdropping on communications within a wireless network by using special software or hardware tools. Sniffing is more intrusive than wireless stumbling, which is looking for the presence of wireless networks. The motives behind wireless sniffing can range from troubleshooting to a malicious attack against a network or individual.

Motives behind wireless sniffing may include a malicious attack against a network or individual.
Motives behind wireless sniffing may include a malicious attack against a network or individual.

Both wired and wireless networks can be monitored or sniffed. Wireless networks generally are easier to sniff because they use radio signals as a method of communication. An attacker could, for example, sit in a car outside a home or business and sniff a wireless network.

Wireless sniffers can be used to find open wireless networks and eavesdrop on them.
Wireless sniffers can be used to find open wireless networks and eavesdrop on them.

Computer networks divide information into pieces called frames. Inside these frames are data packets. Wireless sniffing might target frames, packets or both.

Targeting frames can reveal the presence of a wireless base station that is set up to remain hidden, and it even can be used to crack older wireless encryption standards. Packet sniffing, which can also be called Internet provider (IP) sniffing, can be used to monitor e-mail or other data being sent over a wireless network by others. It also can help a network administrator watch for and diagnose network problems.

To sniff wireless networks, special software known as a sniffer is used to monitor network traffic. Networked computers and devices typically look only at frames and packets that are addressed to them. Sniffing software looks at all frames or packets, regardless of which computer the information is intended for. The wireless card or chipset and drivers that are used must be capable of this, and they must be compatible with the software used.

Wireless sniffing typically has two types of modes: monitor mode and promiscuous mode. In monitor mode, a wireless adapter is instructed to listen for the radio messages broadcast by other wireless devices without broadcasting any messages of its own. This type of sniffing is nearly impossible to detect because the attacker does not broadcast any messages. In promiscuous mode, a sniffer becomes associated with a particular wireless access point. This allows all data on the access point to be monitored, but it could expose the sniffer.

Sometimes a malicious intruder will use information gathered during a wireless sniffing session to imitate another machine. This is known as spoofing. Wireless sniffing can be used to enhance security as well. Wireless sniffing also can be used to perform intrusion detection — watching for attackers or intruders on a network.

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Discussion Comments


I will have to say that our technology is moving forward so fast these days, that there is absolutely no way that we regular folks can keep up with it.

I know some claim that ignorance is bliss, but I would actually say that it can be a little dangerous. Sniffing can be really serious business, but most people don’t even know that it exists.

It’ll be a relief, actually, when things slow down a little for we regular Joe’s to catch up and catch on to what is going on with our technology.

I know all of the techno buffs out there probably would love to hang me up by my toes for that little statement, but most of us either aren’t able or don’t have the inclination to delve into technology the way that they do.


Call me crazy, but I guess I am one of those folks who indulges myself in conspiracy theories. As such, I’ve thought for years that we all ought to be a little more careful with our technology.

To me it is simply common sense to realize that if there are such things as sniffers out there, that we ourselves can indeed be sniffed. As such, I have reservations about some of the things that I will let hang out online.

I do shop online and such as that; but I’m careful. And I never put any kind of ultra personal or precious data anyplace online, no matter how secure it is supposed to be.

You never know when somebody might intentionally try to get to that information, or even do it just for kicks.


I am not sure about wireless versus cable but I think that is a great question.

I have read that Cable Modem is a little less secure than DSL... now if I only knew what those terms meant...

I so appreciate IT people for just these reasons, the software and technology are always changing so they have a lot to keep up with!


@wander - I am pretty naive when it comes to tech security, so I had not heard of using https instead of http, but what a great tip! I will pass it on to my other naive to internet security friends.

I have heard lots of accounts of identity thefts I just had not realized that using free wireless could be an easy way to be 'sniffed'.

I love the convenience of wireless internet usage but are you only sniffed through wireless internet and not cabled internet?


@letshearit - I stopped accessing my social networking sites from wireless Internet cafes along time ago because there was just too much information on those sites that could be easily picked up through wireless sniffing software. I couldn't help but worry that someone could steal my credit card information, my friends list, or even where I lived.

Nowadays a lot of sites are doing more to prevent wireless sniffing by offering an encrypted version of their site. You have to turn this option on though. A good example of this is with Facebook. To ensure your privacy your address needs to read "https" at the beginning, not "http".

It is amazing to me how many people don't know about this extra security feature. I had to get my friends to switch over because they had no idea.


When you are using a source of free wireless Internet, especially in a public place such as a coffee shop or hotel it is a terrible idea to send any sensitive data over the Internet. Wireless sniffing is very easy and people with a little know-how can easily lift things like passwords and personal information from your signal as it travels through the air.

Some examples of wireless sniffing have popped up on the news showing that someone can pull dozens of passwords from the air in a matter of minutes because people carelessly log in to accounts while in public spaces. A lot of the time they don't use a secure format so their information is available for anyone with the right software to see.

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