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Network Security - Man-in-the-Middle (MitM) Attacks

By IncludeHelp Last updated : July 27, 2024

In the previous tutorial, we went through the two most common types of cyberattacks: DoS and DDoS attacks. In this tutorial, we'll explore another type of cyberattack known as Man-in-the-Middle (MITM) Attack. We'll understand how they work with real-world examples and some preventive measures.

What is a Man-in-the-Middle (MITM) Attack?

A Man-in-the-Middle (MitM) attack happens when an attacker interrupts communication between a user and an application, typically to steal data, inject some malicious content, or modify the shared information. The attacker effectively places themself between the transmitter and the recipient, thus the phrase "man-in-the-middle."

How Do MitM Attacks Work?

MitM attacks mainly involve two main stages: interception and decryption.

1. Interception or Interruption

The attacker intercepts the communication by various means such as:

• IP Spoofing: In IP Spoofing, the attacker changes IP addresses to make it look like they are another legitimate user or device
• DNS Spoofing: In DNS Spoofing, the attacker changes the DNS records to send users to a fraudulent website instead of the actual website. When users try to visit a legitimate site, they are unknowingly directed to a malicious site controlled by the attacker.
• Wi-Fi Eavesdropping: In Wi-Fi Eavesdropping, an attacker sets up a fake or rogue Wi-Fi network with a name similar to a legitimate one. This deceives users into connecting to it. Once connected, the attacker can interrupt and manipulate the users' internet traffic.

2. Decryption

Once the communication is intercepted, the attacker needs to decrypt the data if it's encrypted. This can be done through:

• HTTPS Spoofing: The attacker uses a fake security certificate to pretend to be a legitimate, secure website.
• SSL Stripping: The attacker changes a secure HTTPS connection to an unsecured HTTP connection, making the data visible in plain text.

Real-World Examples of MitM Attacks

Example 1: Wi-Fi Eavesdropping

Suppose you are at a cybercafe using the free Wi-Fi. An attacker sets up a fake Wi-Fi hotspot with a name similar to the actual one. When you connect to a bad network, the attacker can intercept all the transmitted data, such as login credentials, emails, and credit card information.

Example 2: DNS Spoofing

An attacker hacks a DNS server and changes the IP address of a real website, like a bank's site. When a user tries to visit the bank's website, he is redirected to a fake site controlled by the attacker. Users may unknowingly enter sensitive information, such as passwords or PINs, which the attacker captures.

Preventive Measures Against MitM Attacks

To get rid of MitM attacks, users can take some preventive measures such as:

1. Using Strong Encryption

We must ensure all communications use strong encryption protocols such as HTTPS. Look for the padlock or tune icon in the browser's address bar to confirm a secure connection.

In this image, the Includehelp.com website uses the secure HTTPS protocol, indicated by the tune icon before the URL, ensuring a secure connection.

2. Using Multi-Factor Authentication (MFA)

Using MFA adds an extra layer of security, making it harder for attackers to gain access even if they intercept login credentials.

3. Keeping Software Updated

We must regularly update all software, including browsers, operating systems, and applications, to protect against attackers and known vulnerabilities.

4. Verify Public Wi-Fi Networks

We should avoid connecting to public Wi-Fi networks without verification. Consider using a VPN to encrypt your internet traffic for added security.

5. Monitor Network Traffic

Regularly monitor network traffic for unusual activity. Use Intrusion Detection Systems (IDS) to detect and respond to suspicious activities.

FAQs on Man-in-the-Middle (MitM) Attacks

1. What are the common signs of a MitM attack?

Common signs include unexpected disconnections, browser warnings about invalid certificates, slow internet speeds, and receiving suspicious emails or messages.

2. Can antivirus software prevent MitM attacks?

While antivirus software can detect some forms of malicious activity, it is not foolproof against MitM attacks.

3. What should I do if I suspect I'm a victim of a MitM attack?

If you suspect a MitM attack, immediately disconnect from the network, change all passwords, enable MFA, and contact your IT department or a cybersecurity professional for further assistance.