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Wifi Eavesdropping: What It Is and How to Prevent It

Patrick Sullivan

Group of coworkers discussing project in office

Remote work is more popular than ever, and this trend shows no signs of slowing down. This means that many people rely on public Wi-Fi networks to get important tasks done.

Public internet access is incredibly convenient, but it also comes with unique security risks. Hackers take advantage of public Wi-Fi using eavesdropping attacks to steal sensitive data from unsuspecting users.

If your team works remotely, you need a plan to prevent Wi-Fi eavesdropping attacks. In this blog, we’ll take a closer look at how Wi-Fi eavesdropping works and what you can do to prevent it.

Key Takeaways

  • Wi-Fi eavesdropping is a practice used by hackers to intercept data on wireless networks.
  • This is often done to steal valuable financial or personal data.
  • There are many Wi-Fi eavesdropping techniques. Some of the most common approaches include packet sniffers and rogue access points.
  • Strengthening your network encryption, authentication measures, conditional access policies, and network structure all help to prevent Wi-Fi eavesdropping.
  • Using a VPN or Secure Access Service Edge  or SASE provider will help protect your online activity when using public Wi-Fi networks.

Understanding Wi-Fi Eavesdropping

Wi-Fi eavesdropping is the process of intercepting data packets sent over a wireless network. This approach is sometimes referred to as ‘sniffing’ or ‘snooping’.

Every time we use the internet, we send and receive data packets. However, if these packets aren’t encrypted, anyone who captures them could decode and read them.

During an eavesdropping attack, hackers will find a Wi-Fi network and use special tools to capture these data packets. In some cases, the hacker may even create a malicious duplicate network with the same name as a nearby network. This gives them even more access to the data sent back and forth as they sit between the user and the internet as they sit and listen to the network traffic being forwarded out to the internet. 

Motivations Behind Wi-Fi Eavesdropping

There are a variety of reasons why cybercriminals use Wi-Fi eavesdropping techniques. These include:

  • Financial opportunities: Roughly 86% of cyberattacks are financially motivated. Wi-Fi eavesdropping is often used to capture credit card numbers and bank login details. Hackers then use this information to conduct identity theft or steal money outright.
  • Intellectual property theft: In the corporate world, proprietary information is valuable. Cybercriminals use Wi-Fi eavesdropping to capture this information and use it for their own gain. They might use it to further their own business, hold it for ransom, or sell it directly to a competitor.
  • Surveillance: Some hackers use Wi-Fi eavesdropping to better understand how they should attack a business or user more effectively. This includes figuring out when companies will be paying vendors or getting paid by clients. This information is used to spearphish a business to potentially redirect payments to bank accounts the hacker controls. 

Risks and Consequences for Business

Organizations should be cautious of Wi-Fi eavesdropping attacks. Anyone who uses public Wi-Fi could be a target, regardless of your industry or the size of your organization. These practices are most common in public places, like cafes, airports, and libraries, but can also happen on home and office Wi-Fi networks.

The biggest risk here is the potential loss of data. Any data transmitted via the internet could be at risk. Not only does this compromise your company’s security, but it also compromises your customers’ security.

If the data breach isn’t contained appropriately, it could result in serious damage to your reputation. Today’s consumers take cybersecurity seriously, and need to be able to trust that you can protect their data.

Successful attacks can result in a loss of sales for your company, and other financial and legal implications. Depending on your industry and location, you may need to pay fines when consumer data is compromised.

Recovering from a Wi-Fi eavesdropping attack takes time. When these attacks are successful, they can disrupt your operations for an extended period of time, resulting in diminished morale and productivity among your team.

Common Techniques Employed by Wi-Fi Eavesdroppers

Wi-Fi eavesdroppers use a variety of different techniques to intercept network traffic and steal data.

Expert Insight

“You can think of a Wi-Fi network like people speaking out loud to each other. People don’t need to join the conversation to hear it, they just listen and focus on taking in the conversation of the person they want to eavesdrop on. In the same way, an attacker doesn’t need to join the network to listen to the ‘conversation’ the computer is having with the wireless access point. They read the wireless radio traffic being broadcast over the air.”

Tristen Cooper, IT Compliance Analyst at Parachute

Packet Sniffing

A packet sniffer is an application that reads data packets traveling through a network. With these tools, eavesdroppers view the content of packets on an unencrypted network. This strategy is typically used to uncover passwords and other pieces of sensitive data.

Packet sniffers are often used for malicious network monitoring, but they can also be used as part of your cybersecurity strategy. Many IT professionals use packet sniffers to diagnose network issues and protect their data.

Man-in-the-Middle Attacks

In a Man-in-the-Middle (MitM) attack, the eavesdropper intercepts communication between two parties. While the sender and receiver think they’re communicating with each other, their messages are actually sent to the hacker and the hacker acts as a broker for the “conversation” between the two parties.

These attacks are more common than you might think. In fact, 35% of online exploitation uses a MitM attack. 

MitM attacks can use rogue access points, which are designed to mimic legitimate public Wi-Fi networks. Hackers will set up these routers near popular public Wi-Fi networks and label them with similar names in an attempt to trick unsuspecting users.

Not only do hackers use this technique to steal data, but they can also use it to send malicious data and conduct more complex cybersecurity attacks. This is because they can alter the data they’ve intercepted before sending it to its final destination. Consider the idea of someone changing the contents of an invoice, changing the bank account and routing information for ACH transfers using a MitM attack. 

When users connect to these access points, the eavesdropper can monitor all of their online activities. They’re also able to alter this web traffic, steering users to phishing sites or malware downloads.

Wi-Fi Pineapple Attacks

Wi-Fi Pineapples are a type of rogue access point. They were originally developed by cybersecurity professionals to conduct penetration testing. However, they have become popular among hackers because they are affordable and easy to set up.

What Are the Signs of Wi-Fi Eavesdropping?

Detecting Wi-Fi eavesdropping is challenging because attackers aim to be as covert as possible. However, there are a few telltale signs of this unauthorized snooping.

Anyone who uses public Wi-Fi networks should learn the signs of eavesdropping to keep their data safe online. While these signs can also be unrelated to eavesdropping, they should always be double-checked for security purposes.

Unexplained Network Slowdowns

If your internet connection suddenly slows down for no apparent reason, it could be a sign that something’s amiss. This is because eavesdroppers take up additional bandwidth on your network or they might be performing a MitM attack.

There are a variety of potential causes for a network slowdown, such as connection issues or high volumes of traffic. However, if you’ve ruled out these causes, it might be a sign that someone is scanning your network.

Unauthorized Devices on the Network

Regularly checking the list of devices connected to your Wi-Fi network is a good practice. Of course, you can’t do this at a public coffee shop or airport, but you can do it at home or the office.

Many modern routers display a list of connected devices on an interface or connected web app. If you notice unfamiliar devices accessing your network, it could be a sign of an intruder. In particular, keep an eye out for unfamiliar devices showing up at odd hours or for prolonged periods of time.

Suspicious Network Traffic

One of the most effective ways to spot Wi-Fi eavesdropping on home or office networks is to use network monitoring tools. Keep an eye out for unexpected spikes in data transmission, particularly to unfamiliar IP addresses or domains. This could indicate data exfiltration or other eavesdropping activities.

Frequent Password Changes

Many networks will automatically prompt users to change their passwords when they detect suspicious activity. If you’re frequently receiving prompts to change your password without initiating a reset, it could be a red flag. Eavesdroppers might be attempting to gain access to your system by resetting the credentials.

How to Prevent Wi-Fi Eavesdropping

There are many steps you can take to prevent Wi-Fi eavesdropping, whether you’re working in the office, from home, or from a public place. Taking these extra steps is essential to protecting your privacy and keeping your entire organization safe online.

Use a VPN in Public Places

A virtual private network, or VPN, is one of the best ways to protect against eavesdropping when you’re working from a public Wi-Fi hotspot. There are many free and affordable VPNs on the market, and they are available for both computers and smartphones.

VPNs encrypt your online activity and route it through a private VPN server. This hides your IP address and ensures that other network users can’t see your online activity.

Modern VPNs are also very easy to install and set up, even if you’re not particularly tech-savvy. Be sure to always turn on your VPN when working in a public place to stay safe. According to a Forbes Advisor study, 43% of respondents had their digital security compromised when using a public Wi-Fi network.

Strong Encryption Protocols

You should always use updated encryption protocols on your networks, particularly if you’re accessing sensitive information. If you use weak encryption standards, you could leave your network exposed.

Instead, opt for robust encryption protocols like WPA3 to keep your networks safe. WPA3 was released in 2018 and offers better protection against brute force and dictionary attacks when compared to its predecessors.

Secure Passwords and Authentication

Your network is only as secure as your weakest password. To keep hackers out, you’ll need to use complex passwords that aren’t easy to guess.

Opt for long passwords, 12 to 16 characters that have a mix of capital and lowercase letters, numbers, and special characters. Change your password as soon as you find indicators of compromise or suspect your account has been breached in any way and only give out your network password to people who truly need it.

You should implement multi-factor authentication for all of your online accounts. While this might make your login times a few seconds longer, it helps keep your company, money, and data safer .

Regular Firmware and Software Updates

When firmware and software manufacturers discover potential vulnerabilities in their products, they release updates to fix the problem. If you don’t install these updates in a timely manner, eavesdroppers could exploit them to access your Wi-Fi networks and your data. Be sure to regularly check for updates for your router, access points, and all connected devices.

Network Segmentation

Network segmentation is the process of dividing your networks into smaller sections for specific purposes. For example, you might create two segments of your office Wi-Fi – one for guests and one for employees. This means that even if an attacker accesses one segment, they won’t have access to the entire network. . We often overlook what is on our networks while we work from home. Out-of-date devices, non-work computers, and other potentially dangerous devices are found on home networks more often than corporate networks. 

Disable Unused Network Services

Modern routers come with a plethora of features, many of which the average user won’t need. These services are a potential entry point for Wi-Fi eavesdroppers. When setting up your network, review your router’s settings to disable any services you won’t use.

Educating Employees and Users

Your employees play an important role in keeping your networks safe. Many Wi-Fi eavesdropping attacks happen because the user doesn’t know how to protect their online activity.

Host regular workshops for your employees to educate them on the latest cybersecurity threats and best practices. In particular, make sure to offer online workshops for employees working from home. They’ll need to know how to protect their home networks and stay safe on public networks.

Additionally, make sure to post clear guidelines for Wi-Fi use throughout your office. Not only will this help your employees, but it will also help any visitors using your Wi-Fi.

In particular, encourage your employees to practice safe browsing habits. Stay away from suspicious links and emails, and only visit sites with HTTPS encryption. If employees must use public Wi-Fi for any reason, encourage them to use a VPN.

You should also have a process in place where employees can express their concerns regarding potential Wi-Fi eavesdroppers. Encourage open communication about security risks, and be sure to follow up right away when employees do make a report.

How a Managed Service Provider Can Help

Keeping your network safe from Wi-Fi eavesdroppers and other cybercriminals is a challenging task for busy enterprises. If you don’t have the resources to put together a comprehensive cybersecurity program in-house, consider working with a managed service provider, or MSP.

MSPs are third-party experts who provide a variety of cybersecurity services. Your MSP will work with your team to configure and monitor your network, and will help you respond to security threats as they arise.