Who Is on My WiFi?

WiFi security is important

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Recently, two Belgian researchers discovered a critical vulnerability in the Wi-Fi Protected Access II (WPA2) implementations on most wireless networking devices that use the protocol. The name of this vulnerability is KRACK (Key Reinstallation AttaCK), and it allows attackers to steal sensitive data, including passwords, credit card numbers, or chat messages.

According to Wired, “Security analysts say it’s a tricky vulnerability to take advantage of, and major platforms like iOS, macOS, and Windows are either unaffected or have already been patched. But given the millions of routers and other IoT devices that will likely never see a fix, the true cost of KRACK could play out for years”.

Why Should I Care Who Is Using My WiFi?

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If you don’t depend on fast Internet access and are a generous person by nature, you might be wondering, “Why should I care who’s on my WiFi in the first place?” The answer to this question has everything to do with security and privacy.

As you may know, most modern wireless networks are encrypted. Wireless encryption ensures that anyone who doesn’t have the encryption password can’t snoop on you and possibly steal your private information. When someone joins your wireless network, either because the person has managed to steal your password or because you gave the person the password yourself, the encryption stops affecting your security with respect to them.

Depending on how your computer and other devices are configured, a stranger who joins your WiFi might gain access to the files that you share among computers, printers, and other connected devices. While it’s certainly possible to restrict access to these files, most people lack the required know-how, and it’s almost always easier to stop the intruder before the gates rather than allowing him or her to enter the town and then locking every door individually.

But perhaps the most important reason why you shouldn’t let strangers use your WiFi is security. The sad truth is that most computer users have terrible habits when it comes to security and seldom take even the most basic security precautions. If someone on your network gets infected by a dangerous strain of malware, the malicious software could spread to other computers and devices on the network. Some types of malware focus specifically on WiFi routers, either using their resources for malicious purposes or taking advantage of their central role to attack as many people as possible.

How Can I Detect Who Is on My WiFi?

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By far the simplest way how you can answer yourself the question “Who’s on my WiFi?” is by checking your router’s logs. Virtually all routers keep some sort of a record of past and current connections, usually stating both the IP address of every connected device and its name.

If notice that an iPhone 8 is connected to your home wireless network even though you don’t own a single Apple device and are sure that neither do your friends and family, it’s possible that the iPhone belongs to someone who has no business being on your network. If your router allows you to disconnect a connected device from the admin interface, don’t hesitate to do so. Just remember to also change your password otherwise the intruder might reconnect the second you go back to minding your own business.

We also encourage you to download a comprehensive WiFi analysis application, such as NetSpot, to understand the reason why someone has successfully joined your wireless network. NetSpot can create an easy-to-understand heat map of your wireless signal strength so you can determine how far from your router someone could be and still have access to your wireless network. What’s more, NetSpot can also give you accurate information about the security of your wireless network as well as the channel on which the network is broadcasted. With the information provided by NetSpot, it’s easy to optimize your WiFi so that strangers can’t steal your bandwidth anymore.