What are evil twin attacks and how do you prevent them?

In a hyper-connected world, consumers want to stay online wherever they go, and they crave convenience to achieve this. Many of us won’t think twice before connecting to free Wi-Fi. It’s a lifesaver, offering easy access to the internet at cafes, airports, and other public spaces.

But have you ever considered that connecting to an unsecured public Wi-Fi source could put your sensitive information at risk? Research shows one in four travelers are hacked while connecting to public Wi-Fi networks.

Evil twin attacks are a poignant threat, both at home and abroad. From personal messages to critical banking information, everything transmitted over these networks is vulnerable to interception by bad actors. 

In this blog, we’ll explore everything you need to know, including:

• What is an evil twin attack? 
• Different types of evil twin attacks
• How do evil twin attacks work? 
• Why are evil twin attacks dangerous? 
• Real-life example of an evil twin attack 
• How to identify an evil twin attack 
• What to do if you fall victim to an evil twin attack 
• How to prevent and protect yourself from evil twin attacks 
• FAQs 

What is an evil twin attack?

An evil twin attack is a type of cyberattack in which an attacker sets up a fake Wi-Fi network that mimics a legitimate one. When users connect to the fake network, the attacker can intercept their traffic and steal their data. 

The risks of an evil twin attack are significant. If an attacker can intercept your traffic, they can steal your personal information. They could also use your device to launch other attacks, such as distributed denial-of-service (DDoS) attacks.

Different types of evil twin attacks

There are several different types of evil twin attacks that cybercriminals may employ to deceive users and compromise their security. Some common variations include:

Basic evil twin

A simple attack where the attacker sets up a rogue access point with the same name (SSID) as a legitimate Wi-Fi network to trick users into connecting.

Deauthentication attack

In this attack, the attacker sends fake deauthentication packets to disconnect users from the legitimate Wi-Fi network, prompting them to reconnect to the malicious evil twin.

Karma attack

When a device is set to automatically connect to known Wi-Fi networks, the Karma attack leverages this feature to trick the device into connecting to the attacker’s evil twin network without the user’s knowledge or consent.

Captive portal attack

The attacker creates a fake captive portal, mimicking the login page of a legitimate network, to steal login credentials or personal information when users attempt to connect.

Evil twin with spoofed MAC address

The attacker not only replicates the network’s SSID but also spoofs the MAC address of the legitimate access point, making it more challenging for users to differentiate between the two networks.

How do evil twin attacks work?

Evil twin attacks involve setting up a fake Wi-Fi network that mimics a legitimate one. It typically entails: 

1. Rogue Wi-Fi setup

The attackers set up a malicious Wi-Fi access point in close proximity to a legitimate public Wi-Fi hotspot, such as in a coffee shop, airport, or hotel. They give the rogue network a name similar to the legitimate one to deceive users.

2. Beacon frames

The rogue access point sends out “beacon frames,” which are special packets that announce its presence and network name. Users’ devices within range automatically detect these beacons and display the rogue network as an available Wi-Fi option.

3. User connection

Unsuspecting users, seeking a Wi-Fi connection, may unknowingly choose the rogue network, assuming it to be legitimate. They connect to the fake network, believing it to be safe and secure.

4. MITM attack

Once connected, the attackers launch a Man-in-the-Middle (MITM) attack. They intercept and monitor the traffic passing between the victim’s device and the internet. This allows them to eavesdrop on communications, steal sensitive data, or manipulate the traffic.

5. Data interception

The attackers can capture login credentials, personal information, financial details, or any other data transmitted over the fake network. This data can be used for identity theft, financial fraud, or further cyberattacks.

6. Spoofing legitimate websites

In some cases, the attackers may redirect victims to fake versions of legitimate websites, fooling them into entering sensitive information, such as login credentials or credit card details.

7. Malware distribution

In more sophisticated attacks, the rogue network can be used to distribute malware or ransomware to connected devices, exploiting vulnerabilities and compromising the victim’s system.

8. Persistence

The attackers may keep the rogue network active for an extended period, continuously luring new victims. This persistence allows them to target multiple users over time.

Why are evil twin attacks dangerous?

Evil twin attacks pose significant risks to both personal and organizational security. They’re considered dangerous because of: 

Data theft

When users unknowingly connect to an evil twin network, cybercriminals can intercept sensitive data transmitted over the network. This can include login credentials, personal information, financial data, and other sensitive details, leading to identity theft, financial fraud, or unauthorized access to accounts.

Man-in-the-Middle attacks

Evil twin attacks facilitate man-in-the-middle (MITM) attacks, where cybercriminals intercept and manipulate communications between the victim and the legitimate network. This allows attackers to eavesdrop on conversations, inject malicious content, or modify data, leading to privacy breaches and compromised communications.

Ransomware and malware distribution

Attackers can use evil twin attacks as a gateway to distribute malware or ransomware to connected devices. By tricking users into connecting to a rogue network, cybercriminals can deliver malicious software, leading to data loss, system compromise, or network-wide infections.

Financial losses

Evil twin attacks can lead to financial losses for individuals and organizations. Cybercriminals can use the stolen data to conduct unauthorized financial transactions, make fraudulent purchases, or steal funds from bank accounts.

Reputation damage

For businesses, falling victim to an evil twin attack can damage their reputation and erode customer trust. Customers may hold the organization responsible for the security breach, leading to a loss of confidence in their services or products.

Real-life example of an evil twin attack

Stealing data in public is more of a threat than you may think. Let’s explore a real-life example.

In a bid to evaluate attendee behavior, a team of journalists set up a fake Wi-Fi Access Point (AP) and used an evil twin attack to see how many unsuspecting users would connect to it. They set up a booth at RSA, one of the world’s largest IT security conferences, and broadcasted eight globally common SSID names. 

They managed to trick an alarming 4,499 Wi-Fi clients into connecting to their rogue AP. Although they didn’t interfere with anyone’s personal data, this experiment shows the ease with which cyber attackers can exploit people’s trust in public Wi-Fi networks.

Even in a highly secure environment like the RSA Conference, thousands of attendees unknowingly connected to the rogue AP, demonstrating the significant risks associated with these attacks. This serves as a stark reminder that anyone, including cybersecurity professionals, can fall victim to such threats. 

How to identify an evil twin attack

Evil twin attacks are designed to deceive users into connecting to malicious Wi-Fi networks that impersonate legitimate ones. Here are some key indicators to look out for: 

Check for network name discrepancies

Pay close attention to the Wi-Fi network name (SSID). If you notice multiple networks with similar names, especially one that exactly matches a known network you use, it may be an evil twin attempting to deceive you.

Verify encryption type

Check the encryption type of the Wi-Fi network. Legitimate public networks often use WPA or WPA2 encryption. If you encounter an open network or one using outdated WEP encryption, it could be an indication of a suspicious network.

Look for HTTPS

Always ensure that websites you visit are using HTTPS encryption. If you connect to an evil twin network, attackers may try to intercept data sent over unsecured HTTP connections.

Examine certificate warnings

If you receive SSL/TLS certificate warnings when accessing websites, it might indicate an attempted man-in-the-middle attack, which is often associated with evil twin attacks.

Check signal strength

Evil twin networks are typically set up to have stronger signals than legitimate ones to attract more users. If you notice an unusually strong signal for a known network, it could be suspicious.

Beware of multiple authentication requests

If you frequently encounter login or authentication requests when connected to a network you’ve used before, it might be a sign of an evil twin attempting to capture your credentials.

Analyze router MAC addresses

Compare the MAC addresses of the routers you connect to. If you notice multiple routers with the same MAC address, it could be a red flag for an evil twin attack.

Trust your instincts

If something feels off about the network or the connection, it’s best to avoid connecting to it. Trust your intuition and prioritize security over convenience.

What to do if you fall victim to an evil twin attack

If you suspect you’ve fallen victim to an evil twin attack, here are the steps you’ll need to take to mitigate the damage:

1. Disconnect from the network: immediately disconnect from the suspicious Wi-Fi network to stop any ongoing data interception or malicious activities.
2. Disable Wi-Fi and mobile data: turn off Wi-Fi and mobile data on your device to prevent any further unauthorized access or data transmission.
3. Change your passwords: change your passwords for all online accounts, especially those accessed while connected to the suspicious network.
4. Scan your device for malware: run security scans using reputable anti-malware software to detect and remove any threats from your device. 
5. Monitor your accounts: continuously monitor your online accounts for any suspicious activities or unauthorized access.
6. Inform relevant authorities: report the incident to the appropriate authorities, such as the network administrator or the establishment where the attack occurred. 
7. Report the incident: if the attack occurred in a public place, report it to the local law enforcement authorities and provide any necessary information to assist in their investigation.

How to prevent and protect yourself from evil twin attacks

Here are some tips on how to prevent and protect yourself from evil twin attacks:

• Only connect to trusted Wi-Fi networks: avoid connecting to open or unsecured Wi-Fi networks and stick to trusted networks with encryption and password protection.
• Be cautious of clicking unknown links in emails or social media posts: refrain from clicking on suspicious links that may redirect you to malicious websites or initiate an evil twin attack.
• Use a VPN: when accessing public Wi-Fi or unfamiliar networks, use a reputable Virtual Private Network (VPN) to encrypt your internet traffic and protect your data from potential eavesdropping.
• Keep software up to date: regularly update your device’s operating system, applications, and security software to patch known vulnerabilities and stay protected against emerging threats.
• Be aware of your surroundings: always remain vigilant about nearby wireless networks, especially if you notice multiple networks with similar names, which could be indicative of an evil twin attack. 
• Check the security of the network: before connecting to a Wi-Fi network, verify its legitimacy by checking the security settings and confirming its legitimacy with the venue or business. 
• Use a password manager: employ a reliable password manager to create strong and unique passwords for each of your online accounts, preventing attackers from gaining unauthorized access.
• Use a secure browser: opt for a browser that has robust security features, such as anti-phishing protection and built-in security mechanisms, to enhance your protection while browsing the internet.

FAQs

What’s the difference between an evil twin and a rogue access point?

The main difference between an evil twin and a rogue access point lies in their intentions. An evil twin is a type of rogue access point that is set up with malicious intent, mimicking a legitimate network to deceive users and capture sensitive information.

On the other hand, a rogue access point refers to any unauthorized or unapproved access point on a network, which may not necessarily be malicious but can still pose security risks.

What are some tools you can use to defend against evil twin attacks?

You can use tools such as Wi-Fi security scanners and analyzers to detect rogue access points. Additionally, implementing strong encryption protocols, such as WPA3, and using virtual private networks (VPNs) can also help protect data transmission from potential eavesdropping and unauthorized access on public Wi-Fi networks. 

How can I tell if I’m connected to an evil twin network?

To see if you’re connected to an evil twin network, carefully check the Wi-Fi network’s name (SSID) to see if it matches the official network. Be cautious of networks with slight variations or misspellings.

Additionally, verify the network’s security settings—legitimate networks usually use encryption protocols like WPA2 or WPA3. Evil twin networks may have open or poorly secured connections. Check the location of the network and be wary if the connection drops or behaves strangely.

Using a Wi-Fi scanner app can help detect nearby networks and identify potential evil twin access points with similar names.

What are the most common ways that evil twin attacks are carried out?

The most common methods for carrying out evil twin attacks include creating a rogue Wi-Fi access point with a similar name to a legitimate network, luring users to connect to it; setting up a captive portal to capture login credentials or sensitive information from unsuspecting users; and using deauthentication attacks to disconnect users from their legitimate network, forcing them to connect to the evil twin. 

Final thoughts

Free Wi-Fi is an attractive lure that bad actors can exploit through evil twin attacks. Despite the convenience, these deceptive tactics take advantage of our trust in public Wi-Fi networks and put our most sensitive information at risk of exposure. You may have already fallen victim and not even know it. 

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