Home computer users who install wireless networks love the convenience of a fast Internet connection from anywhere in their homes.
Some of their neighbors might agree — because it’s free.
Wireless coverage doesn’t stop at a property line or apartment wall, so users who don’t secure their networks may be giving their neighbors a free ride, or tempting a teenage hacker who lives down the block.
“They could access your hard drives, get into your personal files, things like that,” said Mike Oldright, manager of Run PC in Longmont. “Most of the time, kids aren’t after that. More than anything, it’s just to see if they can get in, period.
“They probably can’t get to much. They could put viruses or remote access software onto your computer. They could theoretically take control of your computer,” Oldright said.
A wireless network that uses a common technology called 802.11b can reach computers in a 300-foot radius outdoors. 802.11g technology can reach more than 1,000 feet.
“I’ve gone to clients who said, ‘I keep getting print jobs on my printer.’ It turns out it was a neighbor two blocks away,” said William Marmie of Affordable IT Services in Lafayette.
The growth of wireless networks has even spawned a new hobby called “war driving” — cruising
around with a laptop to find unprotected wireless networks. Some war drivers build antennas out of Pringles cans to help them find stronger wireless signals.
Usually, war drivers want nothing more than to convince people to take more security precautions.
The name is a reference to “war dialing.” Early in the home computer age, hackers would call random phone numbers, looking for an unprotected modem. The hobby was featured in the 1983 Matthew Broderick movie “WarGames.”
In June, war drivers across the world took part in WorldWide WarDrive 4. For one week, war drivers tried to find all the wireless access points they could and plot them with the Global Positioning System. More than a quarter of the networks they found were completely unprotected, and only 38 percent used Wired Equivalent Privacy, a standard security feature for wireless networks.
“There are just oodles and oodles of open stuff,” said Ian Underwood, a network analyst in Broomfield, who mapped Denver for WWWD4 using the alias Agent Green.
“At the very least, somebody is surfing the ’Net on their dime,” Underwood said. “At the worst, they could say, ‘Oh, the C drive is insecure. Let’s see what’s on it.’ It could turn into a real disaster.”
Underwood, who became interested in wireless security while taking a networking class at the University of Massachusetts, worries that criminals could use open wireless zones to gain untraceable access to the Internet.
“Any covert action that can be done through a wireless gateway can pretty much be hidden from law enforcement,” he said.
However, that is not yet a widespread problem.
“There are very few cases I’m aware of where wireless networks have been abused in an illegal way,” Underwood said.
Some people even keep their networks open on purpose. Unprotected wireless networks are common near the University of Colorado, Marmie said, because one student will sometimes let an entire apartment building piggyback off his wireless connection.
“It’s somewhat a matter of trust, but it’s also a matter of practicality,” Marmie said, noting that most college students want nothing more sinister than a free Internet connection.
Most home users don’t need extra software to secure their networks from casual hackers.
“Your best protection is to keep your normal network securities,” Marmie said.
Each wireless network has a name called an SSID. Linksys, maker of a popular brand, ships its systems with the default SSID “linksys.” As a result, hackers can often find a network with that name.
“The first way to protect yourself is to change the SSID to something other than ‘linksys,’” Oldright said.
Users also can protect their wireless systems through WEP encryption and MAC address filtering. Wireless setups come with WEP encryption capabilities. It takes 10 to 20 minutes to set up, Oldright said. MAC address filtering allows only certain computers on a network.
“Each (wireless) card on the planet is supposed to have a unique MAC address,” Oldright said. A hacker or freeloader shouldn’t be able to get on a network that uses MAC address filtering.
“If both of these technologies are applied, it’s very difficult to crack a wireless network,” Oldright said.
Not surprisingly, determined hackers have found ways around encryption. A program called AirSnort “listens” to network traffic and can guess encrypted passwords. Oldright estimates that it would take a month of listening on a typical home network before AirSnort made a correct guess.
But it’s unprotected networks that war drivers like Underwood see as the biggest problem.
“It’s not very difficult” to protect a network, Underwood said. “People have to take care and be a little more vigilant.”
Joe Hanel can be reached by e-mail at firstname.lastname@example.org.