War Driving

Equipped with wireless devices and related tools, and driving around in a vehicle or parking at interesting places with a goal of discovering easy-to-get-into wireless networks is known as war driving. War-drivers define war driving as “The benign act of locating and logging wireless access points while in motion.” This benign act is of course useful to the attackers.

9.1 War chalking

War chalking is the practice of marking sidewalks and walls with special symbols to indicate that wireless access is nearby so that others do not need to go through the trouble of the same discovery. A search on www.google.com with key words “war driving maps” will produce a large number of hits. Yahoo! Maps can show "Wi-fi Hotspots" near an address you give.

Figure 3: War Chalking Symbols

The typical war driving equipment consists of a laptop computer system or a PDA with a wireless card, a GPS, and a high-gain antenna. Typical choice of an operating system is Linux or FreeBSD where open source sniffers (e.g., Kismet) and WEP crackers (e.g., AirSnort) are available. Similar tools (e.g., NetStumbler) that run on Windows are available.

War drivers need to be within the range of an AP or station located on the target network. The range depends on the transmit output power of the AP and the card, and the gain of the antenna. Ordinary access point antennae transmit their signals in all directions. Often, these signals reach beyond the physical boundaries of the intended work area, perhaps to adjacent buildings, floors, and parking lots. With the typical 30mW wireless cards intended for laptops, the range is about 300 feet, but there are in 2004 wireless cards for laptops on the market that have 200mW. Directional high-gain antennae and an RF-amplifier can dramatically extend the range.