Nessus has plugins that can pull out current (or previously used) wireless service set identifiers (WiFi SSIDs) that Windows and OS X systems have connected to in the past. The following plugins are used:
- Mac OS X Wireless Networks List (63340) - This new plugin reports a history of wireless networks used by the target system.
- Windows Wireless SSID (WMI) (25197) - Using WMI, this plugin reports the existing wireless network the target host is currently using.
For both of the above checks, you must enter valid system credentials for the target hosts. Below is a sample report from an OS X system:
A listing of previous wireless networks to which a Mac OS X host has connected.
The plugins mentioned above are useful in the following scenarios:
- If a Windows computer is connected to the internal wired network, you can easily identify hosts that may have also accidentally (or intentionally) connected to unsupported wireless networks (such as the coffee shop next door).
- The history of wireless networks for OS X hosts can indicate where the particular host has visited. For example, bars, restaurants, and airports often have an SSID that identifies the location.
- The name of the wireless network itself can sometimes indicate the security level. For example, if you find hosts that have connected to an SSID of "Linksys," you can be fairly certain they were using a wireless network without encryption. Since "link sys" is the default SSID for several different wireless routers, users who have left the default SSID rarely will configure the router to support encryption.
- If an attacker presented a wireless network to your users and used it to attack systems, you can see which Windows hosts are currently connected to it and which OS X systems may have connected to it in the past.