If my WiFi light is on, does that mean someone may be accessing my computer?

General · 02-21-2015, 08:13 AM

I have a netbook with a WiFi card. I live in a neighborhood with a high concentration of computer professionals.

My system has the WiFi drivers installed, but I never used the WiFi card myself and never installed any special software for connecting to a WiFi router.

Recently, I noticed the WiFi indicator light is sometimes turning on. I disabled the wired connection and found I had no connection, so it does not appear that the WiFi card is connecting anywhere. Could someone possibly be hacking into my computer via the WiFi card on my computer? Is that possible?

veerain · 02-21-2015, 08:27 AM

You have to first setup your wifi then only can someone access it. Do you use auto network configuration software like Network Manager? Check them to be sure.

Read the manual about your wifi card to see when and why it lights on.

General · 02-21-2015, 08:35 AM

I never ever setup the WiFi card. Debian's installer installed the non-free drivers for it, but I never took any steps to setup the card. I only setup the wired Internet. I don't use any network manager software and don't think any is installed. I deleted every package I could find seemingly related to WiFi.

allend · 02-21-2015, 09:05 AM

To find the status of network interfaces use 'ip link'. This is the output on the computer I am using.

Code:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT qlen 1000
    link/ether 70:5a:b6:28:a1:9b brd ff:ff:ff:ff:ff:ff
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DORMANT qlen 1000
    link/ether c4:17:fe:af:86:b1 brd ff:ff:ff:ff:ff:ff

The wired interface, eth0, is DOWN and so not in operation.
The wireless interface, wlan0, is UP and in operation.

Wireless connections can also be checked with 'rfkill list'. Again, this is the output I currently see

Code:

0: phy0: Wireless LAN
        Soft blocked: no
        Hard blocked: no
1: acer-wireless: Wireless LAN
        Soft blocked: no
        Hard blocked: no

The soft blocking can be done via software e.g. rfkill block <suitable option> to disable.
The hard blocking usually refers to a hardware switch on the computer.

fatmac · 02-21-2015, 03:20 PM

....& you could just remove the card from your machine if you never want to use it.

Head_on_a_Stick · 02-21-2015, 03:30 PM

Blacklist the wi-fi module -- I do this for my webcam & bluetooth.

Use this to find the module name:

Code:

lspci -k|grep -iA2 net

It will be listed as the "kernel driver" for you wireless card.

Then create a file at /etc/modprobe.d/blacklist.conf with this content (add this line to the file if it already exists):

Code:

blacklist <module name>

LinuxUser42 · 02-22-2015, 10:33 PM

Being on a Netbook, I am wondering if your hitting a key that turns it on and off. On one of mine, it is on the same card as Bluetooth and I can turn it so I have BT and no wireless, wireless and no BT, both on, or both off, via a hardware switch, independent of the OS.