Clients can be found on both wired and wireless networks. A client could either be a server, a printer, or even a NAS (Network Attached Storage) device. Usually, makeshift networks that had been setup from out of the blue without any prior planning whatsoever lack any printers or servers; the only thing present in these ad-hoc installations are other people's machines, because a network of computers is the easiest type of network to establish. A client can also be used by crackers to run amok on any given notebook PC or PDA using wireless technology. What's more, there are many ways for a cracker to crack through the passwords or passphrases used for WPA or WPA2 protocols; if you're using the outdated WEP standard, you're even more susceptible.
With that said, when it comes to WiFi client protection, several important factors and circumstances must be considered in order to ensure your wireless connection's overall security. For instance, because the majority of users have no idea how to protect their machines from the ravages of cyberspace and since most propriety operating systems being used in personal computers nowadays are Microsoft-based (which means they're susceptible to hacker attacks), dedicated and competent crackers have plenty of wiggle room to use when it comes to doing what they do best.
The combined factors of the notoriously threat-prone Windows operating system and the general ignorance of the everyday, average user when it comes to cyber security allows hackers quite a lot of leeway to pretty much do whatever they want to a WiFi client. Moreover, a laptop that uses a wireless connection is one of the most exposed and hacker-vulnerable setups in existence. To be more exact, an office notebook or any other mobile device that is linked to the Ethernet can still have its Wireless Network Interface Card installed and configured in peer mode although the office from which it came from has not submitted a WiFi network, thus leaving it exposed to hacker attacks by default.
A Wireless Network Interface Card operating in peer mode can also deploy the probe request frames usually involved during wardriving expeditions. These probe request frames are delivered at regular intervals in an effort to link up with another gadget that has an identical SSID.Ergo, NetStumbler or any other wireless sniffer program can then be utilized in order to locate wireless devices configured in peer mode. From there, a hacker could connect to the laptop and exploit any number of its vulnerabilities at his behest, which would then allow him root access to the machine.