How Can I Know If Someone Is Stealing My Wi-Fi?

If you notice slowdowns in Netflix streaming or web browsing, chances are that someone will turn off your internet. While it might just be a neighbor who is too cheap to buy your own data plan, you need to know for sure if someone is stealing your Wi-Fi and increase your security accordingly. Here’s how.

Dear Lifehacker,

Lately, it seems like my high speed connection is stuck and I have an eerie feeling that someone is stealing my bandwidth on my Wi-Fi network. How can I know if other people are hijacking my Wi-Fi and how can I stop them if they are?


Paranoid or not?

Dear PoN,

Apart from the fact that your Wi-Fi-moocher can slow down your connection, people connected to your network may also have access to some of your shared folders (depending on what security measures you use) and someone might even use your connection for illegal things. This can give you some difficulty if, say, you receive an angry email from your ISP about not using BitTorrenting.

Don’t worry though, we can help you find out if someone is stealing your Wi-Fi and help you put an end to it. (Note: If it turns out that no one is using your Wi-Fi, you can check out our guide to fixing a slow Wi-Fi connection .)

Without further ado, there are several methods for detecting wireless intruders.

Low-tech method: check your wireless router lights

Your wireless router should have indicator lights that show your internet connection, wired network connections, and any wireless activity. One way to tell if someone is using your network is to turn off all wireless devices and see if the wireless light is blinking. The problem with this method is that you might have a lot of other Wi-Fi devices (like your TV, smartphone, or game console) that need to be turned off, and the process doesn’t give you a lot of additional information.

This is still a quick and dirty way to confirm your suspicions. For more information, check using the administrative console or the software tool below.

Network administration method: check your router’s device list.

Your router’s administrative console can help you learn more about wireless activity, which is where you need to go to change your router’s security settings. To log into the console, enter the IP address of your router into a web browser window. Some routers have default IP addresses (assuming you haven’t changed any settings) that you can use to access the admin panel.

Otherwise, you can find this address in Windows by going to Command Prompt (press Win + R, then type cmd ) and then type ipconfig in the window and press Enter. The number next to “Default Gateway” or “IPv4 Address” is what you are looking for.

Mac? Open System Preferences> Network. Switch to your active connection (indicated by a green dot) and look for a long string of numbers under the “Status” text. You can also click Advanced …> TCP / ICP and get the number next to IPv4 Address.

Then enter this IP address in the browser window. You will be prompted to log into your router. If you haven’t changed the defaults, your router documentation will have login information, which usually uses a combination of “admin” and “password” or blank fields. (Note: For security reasons, you must change the login as soon as you log into the router console so that a hacker cannot do it for you.)

Attached devices

All routers are different, but once you get into yours, you will need to look for the section related to connected devices (Device Manager, Connected Devices, My Network, etc.). It should provide a list of IP addresses, MAC addresses, and device names (if found) that you can find. Compare the connected devices with your equipment to find unwanted users.

Note . Not all connected devices are displayed in the DHCP list on routers, but only DHCP clients – devices that automatically received their IP address from the router. However, a stealthy hacker can break into your network with a static IP address bypassing this DHCP table. Therefore, you need to refer to the actual wireless client list and not the DHCP list. For example, on Linksys routers, you can find it behind the wireless MAC filter feature that needs to be enabled so you can display a list of MAC addresses of all connected devices (static or DHCP).

What to do if you find an unauthorized device

As mentioned below, verifying that your wireless security is using WPA2 encryption (and setting a new password) will prevent unauthorized users from accessing your Wi-Fi network (and disable everyone on your network until they provide a new security key ). However, IP addresses and MAC addresses alone will not help you identify criminals.

Detective method: use network monitoring software.

It’s good to know how to get to the network admin panel, but you might also need more advanced network auditing or investigation. This is where the help comes MoocherHunter. MoocherHunter, part of the free OSWA (Organizational Systems Wireless Auditor) -Assistant, is used by law enforcement agencies to track Wi-Fi users. The software’s description states that it can determine the location of a wireless hacker from the traffic it sends over the network, with an accuracy of two meters.

The software does not run on Windows as an executable file; rather, it needs to be burned to a CD and then used to boot the computer. The idea is that you will walk around and use your laptop (and the directional antenna on your wireless card) to triangulate the physical location of the Wi-Fi moocher.

We are not encouraging you to use this tool to take any real action (like knocking on a neighbor’s door and have physical confrontation) based on the results of the software, but this is another way to learn more about who, if anyone, can be used by your wireless network.

If you have a new router or router based on mesh setup (such as Eero, Google, or Luma routers), you should do a quick search in the app store of your choice to see if there is a corresponding network management application.

While your router may not have debuted with a partner app, all companies like Asus, D-Link, Netgear, and Linksys have network management apps that make managing your wireless network easier than finding your IP address and information for login to the router. These router apps will show you which devices are connected to your network, which ones are consuming bandwidth, and scan for potential issues (like unwanted guests on your network). You can even run firmware updates from some applications, helping to keep your network security up to date.

Moving Forward: Improve Wi-Fi Security

You didn’t mention what type of wireless security your network uses. Legacy security protocols such as WEP and WPA should be avoided as they are quite insecure. If you are using the more modern WPA2, make sure you are using WPA2-AES instead of the less secure WPA2-TKIP.

Unless your connection is secured by a strong password and modern encryption scheme, your Wi-Fi is very vulnerable to anyone looking for a free ride. (If you’re not sure what type of encryption your network uses, go to the wireless properties, which should determine the type of security.)

If you have followed all the steps and you are unable to identify any Wi-Fi seekers and your browsing still seems slow, you might want to turn your thoughts on other options to speed up your internet .

For knowing everyone who connects to you …


Life hacker

This article was originally published in January 2011 and was updated with new information in August 2017 and again in October 2019.


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