Can WiFi detect you even if you aren't connected

Question

I've read that the way WiFi works is that your computer sends out requests looking for any WiFi it recognizes. I use a MAC spoofer but if there is a WiFi in range before I have time to spoof my MAC address, will the WiFi be able to see my MAC address?

Answer 1

I've read that the way wifi works is that your computer sends out requests looking for any wifi it recognizes.

That depends on the configuration of both the access point (AP) and your device.

Most APs periodically emit beacon frames, where they broadcast their presence along with the wifi's name (SSID), capabilities and other information. Your device can stay entirely passive and listen to these broadcasts without sending a single frame.

On the opposite, you can actively discover wifi networks by sending probe requests. This way, your device publicly asks for available APs, along with your MAC address, supported connection types, etc. APs that match these specifications will reply with a probe response frame.

Note that a probe request can also ask for specific SSIDs. This is especially common for smartphones and raised privacy concerns in the past, since these broadcasts can be easily sniffed.

So Yes, unless you are sure you keep your network card entirely passive before spoofing the address, the AP (or an attacker sniffing the wifi traffic in your area) may capture your MAC.

Answer 2

Yes. Monitor mode allows one to listen for packets across all WiFi bands, unlike promiscuous mode which allows to listen for packets on the connected network (local LAN).

Answer 3

Your best option is to ensure your wifi interface is down prior to using macchanger. After you have successfully updated your macid, you can enable your wifi interface.

Also, if wifi is not required, keep it turned off at all times. This will prevent your device from sending probe requests to other wifi devices.