How to tell if your WiFi is being stolen

BBC MundoTecnología. May 11 2015

It’s 9 pm and every day you are about to see a new chapter of your favorite series on your computer. But as every day, wireless internet signal seems slow at the same time.

“It is not normal to go so slow,” you think. And your sense of relaxation begins to dissipate. You despair. “Not loading”, exclaim, while pressing the keys insistently. “Why is it not loading?”. And no one to answer you, you get angry.

If you are in this situation frequently, you should perhaps think that someone else is connecting to your wireless network without your knowledge.

But how do I know? And above all, how to avoid it?

 

We’ll tell you step by step.

1. Suspicion.

The first clue you already have: your internet becomes slower at certain times of the day and does recurrently.

And the second one you get it from your router. Turn off completely all the wireless devices in the house. If the light intended for the wireless device, sometimes referred to as WLAN, continues to flash, suspect. You could be the victim of a network thief.

2. Find the thief.

You have the suspicion, so now you must rule out other options like you’re using a wireless network with low speed and too many computers have connected to it, or even physical obstacles exist that prevent you make the most of it.

Before accusing anyone, you should discard the option of having too many computers connected to a network with a slow speed.

To do so, the experts recommend installing on your computer, smartphone or tablet a program showing the devices connected to the network that way.

There are several free options on the market, as Fing, for mobile devices with both Android and iOS operating systems; Network, Discovery or Net Scan exclusively for Android; and IP Network Scanner or iNet for iOS.

And there are also options for desktops: Angry IP Scanner or Wireshark for various platforms and Wireless Network Watcher and Microsoft Network Monitor for Bill Gates’ company devices.

These programs identify the intruder if connected at that moment.

All these programs indicate how many devices are connected to the wireless network, each identified with an IP address, a numeric label that refers to an interface that is assigned by the router, and MAC address. The latter uniquely identifies the network card and not dependent on the connection protocol used or the network. Usually it’s assigned by the manufacturer and can hardly be changed.

So if the program you decided to use indicates that more devices are connected to your Wi-Fi, there is a thief in sight.

3. Find out if they connected before.

These programs detect intruders, but only if they are using the network at that moment.

However, there are ways to tell if connected during the rest of the day.

For this you need certain information from the router: IP address, a series of three by three numbers separated by points.

This figure can be found in the device manual. Otherwise, you can search.

If you have a Mac, click on the wireless icon in the bottom of the screen. The menu displayed select Open Network and Sharing Center resources, and then Local Area Connection or Wireless Network Connection. Pressing Details will open another window. The IP address identified as IPv4 Default Gateway is the IP address of your router.

And if you’re using a Windows computer, go to search and type “ipconfig/all”, then Wireless LAN and last physical address. This will give you the address of the router.

Once you’ve got that number, you must enter it in the browser. So you will access the website of router.

After entering your password, you’ll meet a record of connections made so far to your wireless network.

4. Protect your network.

Maybe you left the wireless network in your home open so all your family members are connected. Or maybe it was not an oversight by your, but a neighbor used one of the many applications available to discover the Wi-Fi keys.

Either way, having a network intruder could bring more problems that at first you might think. They may have access to information that you have stored in the connected computers, and in the most extreme cases, they might commit a crime in your name, such as downloading child pornography, for example.

To avoid this, the first thing you should do is change the password that the wireless network has by default, replacing it with a more complex one.

In that sense, James Lyne, from the expert company in Internet security Sophos, recommended BBC Mundo avoid putting a word and favored the combination of letters and numbers.

“It’s safer ‘MeGustaBBCMundo123’ that ‘BBCMundo'” he said.

For the expert, another trick to a secure password would think of the words to your favorite song and choose a verse. “Your password will be so much longer and really difficult to decipher.”

After changing this key, you could also configure the router to allow only devices with specific MAC addresses to connect.

This would make more difficult to access your wireless network, and may not have to worry because it does not load your favorite series.