Man-in-the-Middle Attacks: What Are They?

A man-in-the-middle (MITM) attack is a form of cyber threat where a bad actor inserts themselves into a conversation between two parties, intercepts traffic, and gains access to information that the two parties were trying to send to each other. It allows attackers to eavesdrop, collect data, and even alter communications between victims. Understanding the mechanics, implications, and defense mechanisms against MITM attacks is essential for protecting personal and organizational data.

Understanding man-in-the-middle attacks

The core concept behind an MITM attack lies in the attacker's ability to position themselves between two legitimate communication channels, effectively becoming the "middle man" without the knowledge of either party. The attacker can then intercept and potentially modify the data flowing between the two parties. This scenario is similar to that of the concept of eavesdropping on a phone call, except for the fact that in the digital realm, the attacker can not only listen but also potentially alter the conversation.

How MITM attacks work

Attackers accomplish this by exploiting vulnerabilities in cryptographic protocols that secure internet traffic. So, to carry out a MITM attack, bad actors target:

Unsecured Wi-Fi networks

Public Wi-Fi networks, especially those operating without robust encryption protocols, are prime targets for MITM attacks. Attackers can set up malicious access points with enticing names, luring the users to connect. Once they get connected, the attacker can intercept any unencrypted data transmitted, including login credentials, financial information, and personal messages.

ARP spoofing

This technique involves the attacker sending out forged Address Resolution Protocol (ARP) packets on the network. These packets trick devices into associating the attacker's MAC address with the legitimate IP address of the intended recipient. Consequently, data meant for the recipient is routed through the attacker's machine, enabling them to intercept it.

DNS spoofing

This method focuses on targeting the Domain Name System (DNS). Attackers manipulate DNS servers to redirect users attempting to access a legitimate website to a malicious clone controlled by the attacker. This allows them to steal login credentials or insert malware into the user's device without their knowledge.

Let's look at some threats and examples of Man-in-the-Middle attacks:

These attacks pose some serious threats from both data protection and even national security standpoints. By gaining access to sensitive data and information through wrongful measures, the attackers can steal credentials and personal information leading to identity theft, financial fraud, trade secrets and leverage this information for ransom, corporate or national espionage or disrupt operations of different kinds.

Email hacking

Attackers can compromise email servers or services to spy on communications and attachments being sent between parties, or alter conversations by inserting their own content or replies, making it seem very legitimate.

Session hijacking

The attackers can take over an active session between two computers to control the conversation and harvest exchanged data. They can target financial transactions, remote system administration sessions or other sensitive communications.

SSL stripping

Removes SSL encryption from traffic between a browser and server so the information sent over HTTP can be read in plain text. This allows the attackers to intercept and access sensitive data entered into login forms, checkout pages, etc.

Mitigating MITM threats

To better protect against MITM attacks, it's important to know how they work and use the right safety measures. Keeping an eye out for threats and making sure to communicate securely are key steps. Some strategies include:

• Always using HTTPS websites whenever possible, as the encrypted communication channel significantly reduces the risk of data interception.
• Be very careful while using public Wi-Fi hotspots that don’t require authentication. Avoid utilizing unencrypted Wi-Fi networks, particularly for accessing sensitive information.
• Multi-factor authentication (MFA) adds an extra layer of security, requiring not only a password but also an additional verification step, such as a code sent via SMS or generated by an authenticator app. 
• Verifying SSL certificates match the intended domain.
• Enhanced awareness about recognizing phishing attempts can prevent credential theft leading to MITM attacks.

Apart from the above mentioned mitigation strategies, it is essential to look at how DNS security steps in to help. DNS filtering technologies, like DNSFilter, leverage advanced threat intelligence to block malicious websites by checking DNS requests. 

These tools are key in protecting against MITM attacks, acting as a strong defense by keeping your internet browsing safe. Try DNSFilter free for 14 days.