The Interceptor is a wireless wired network tap. Basically, a network tap is a way to listen in to network traffic as it flows past. Most tools are designed to pass a copy of the traffic onto a specified wired interface which is then plugged into a machine to allow a user to monitor the traffic. The problem with this is that you have to be able to route the data from that wired port to your monitoring machine either through a direct cable or through an existing network. The direct cable method means your monitor has to be near by the location you want to tap, the network routing means you have to somehow encapsulate the data to get it across the network without it being affected on route.
The Interceptor does away with the wired monitor port and instead spits out the traffic over wireless meaning the listener can be anywhere they can make a wireless connection to the device. As the data is encrypted (actually, double encrypted, see how it works) the person placing the tap doesn’t have to worry about unauthorized users seeing the traffic.
This project has been built and tested on a Fon+ but should in theory work on any device which will run OpenWrt and has at least a pair of wired interfaces and a wireless one
This isn’t intended to be a permanent, in-situ device. It is designed for short term trouble shooting or information gathering on low usage networks, as such, it will work well between a printer and a switch but not between a switch and a router. Here are some possible situations for use:
- Penetration testing – If you can gain physical access to a targets office drop the device between the office printer and switch then sit in the carpark and collect a copy of all documents printed. Or, get an appointment to see a boss and when he leaves the room to get you a drink, drop it on his computer. The relative low cost of the Fon+ means the device can almost be considered disposable and if branded with the right stickers most users wouldn’t think about an extra small box on the network.
- Troubleshooting – For sys-admins who want to monitor an area of network from the comfort of their desks, just put it in place and fire up your wireless.
- IDS – If you want to see what traffic is being generated from a PC without interfering with the PC simply add the Interceptor and sit back and watch. As the traffic is cloned to a virtual interface on your monitoring machine you can use any existing tools to scan the data.
You can download Interceptor here:
Or read more here.