Man-in-the-middle Attack

What is a Man-in-the-Middle Attack?

Man-in-the-middle (MITM) attack is a common attack method where hackers eavesdrop on an active communication channel between two users. As the name implies, the attackers position themselves in a spot to intercept the communication and retrieve essential information.


Key Takeaways

  • In MITM attacks, hackers eavesdrop on active communication channels between two users to steal confidential information
  • The most common method of executing the attack is leading two victims to believe they are communicating with each other while attackers intercept all their communication.
  • Hackers use methods like sniffing and session hijacking to execute man-in-the-middle attacks.
  • The most common man-in-the-middle attacks are DNS spoofing and ARP spoofing.

How a Man-in-the-Middle Attack Works

The most common method of executing a man-in-the-middle attack is where an attacker leads each target to believe that they are communicating with each other. In the real sense, they are revealing their information to the attacker.

In an analogy, Mary and Paul are the targets, while Eve is the attacker. Eve wants to intercept the communication without being detected and will, therefore, convince Mary that she is Paul and trick Paul that she is Mary. Both targets will reveal their information without knowing, hence the term man-in-the-middle attack.

Methods Used to Execute Man-in-the-Middle Attacks.

The following are the methods used to carry out man-in-the-middle attacks:

  1. Sniffing

There are numerous tools for capturing data packets that enable attackers to inspect data traffic. The devices have monitoring functionalities that allows cyber adversaries to identify hidden packets, such as data traffic addressed to a specific host. Once the tools sniff the packets, attackers can eavesdrop on the communication and steal essential information.

  1. Session Hijacking

Session hijacking is an attack method where a hacker hijacks an active web session. For example, when you log in to a web application, the login mechanism generates a random temporary session token used in future logins instead of requiring you to input your credentials every time.

Cybercriminals can use sniffing methods to determine which traffic has sensitive information and identify the user’s session token. The attacker can then make requests posed as the user, while the web server responds thinking it is responding to the legitimate user.

  1. SSL Stripping

HTTPS protects users from attacks, such as DNS spoofing and ARP attackers. As a result, cyber adversaries use SSL stripping methods to scan and intercept data packets in a network. Then, the attackers modify the HTTPS address requests and route them to an equivalent HTTP endpoint. This tactic forces the user to request a server without encryption, enabling the hackers to access the requests and responses in plain text.

  1. Packet Injection

While using the data packet capturing tools, attackers can use their monitoring capabilities to inject harmful data packets in a network communication stream. Attackers use the legitimate data to hide the malicious packets so that they appear safe. The hackers must first sniff the desired packets before injecting the harmful packets.

Common Man-in-the-Middle Attacks

  1. DNS Spoofing

DNS spoofing is an attack method where a malicious cyber actor introduces corrupted DNS cache data to a target host. The altered DNS cache information then attempts to communicate with another host using the trusted domain name.

As a result, the victim provides sensitive information without knowing that it is going straight to the attacker. The victims share confidential information to a trusted domain but not to the intended recipient.

  1. ARP Spoofing

ARP is an acronym for Address Resolution Protocol. Its purpose is to relay IP addresses as physical MAC addresses within a network. Once a host requests to communicate with another host with a specific IP address, the request references the ARP cache to relay the IP address as a MAC address.

Now, attackers use their MAC addresses to respond to host requests. The first place some packets precisely to sniff an active communication between two hosts. The attackers use ARP spoofing attacks to gain access to valuable information, such as session tokens exchanges.

How To Detect a Man-in-the-Middle Attack

One of the primary methods you can use to detect a man-in-the-middle attack is implementing tamper detection systems. The systems alert a network admin immediately it identifies unusual network behavior or patterns.

You must also actively scan your network to determine if there are signs of data or communication interceptions. You might not be able to detect a man-in-the-middle attack until it is too late without active scanning.

Best Practices for Protecting Yourself Against Man-in-the-Middle Attacks

  1. Robust Wi-Fi Encryption

Implementing strong WAP/WEP encryption on your Wi-Fi access points is an effective control for preventing unauthorized users from connecting to the network. Wireless access points lacking robust encryption schemes can enable attackers to execute brute-force attacks, gain unauthorized access, and perpetuate a man-in-the-middle attack.

  1. VPN

A VPN (a virtual private network) provides users with a secure network for transmitting sensitive information in an insecure network. VPNs are designed to use key-based encryption where both hosts must exchange the right pair of keys for accessing shared information. It protects your communication from unauthorized access or interception.

  1. Health Router Login Credentials

Always ensure to change the default router login since default credentials are easy to guess. It is also essential to create strong credentials that cannot be hacked easily. Attackers target routers with weak credentials to change the victim’s DNS server to a malicious server. They may even plan a malicious program on the router that sends all communication to a remote server