Man-in-the-Middle Attacks: A Hidden Threat to Your Cybersecurity

In the old days, when encryption was not so common, there were major attack types that were quite easy to deploy, yet it could be extremely hard to detect, known as MiTM attack or Middleman Attack. The Middleman Attacks are a serious security concern because they can allow the attacker to eavesdrop on, or even intercept, sensitive information, such as passwords, credit card numbers, personal messages, etc.

Today, we are going to learn what it is, how it works, and how we can avoid it.

What is a Middleman Attack and why it is dangerous

A Middleman Attack is a type of cyberattack where an attacker intercepts and alters the communication between two parties who trust each other. The attacker can spy on the conversation, change the messages, or insert new ones. The attacker’s aim is usually to steal sensitive information, such as passwords, credit card numbers, or personal data, or to cause harm, such as spreading malware, phishing, or spoofing.

A Middleman Attack involves three parties: the client, the server, and the attacker. It can happen in any network environment where there is a chance of interception, such as public Wi-Fi networks, unencrypted websites, or compromised devices. From the attackers side, there are various methods to get in between the two parties, such as ARP spoofing, DNS poisoning, ICMP packet spoofing, or SSL stripping.

A Middleman Attack can have serious consequences for both individuals and organizations. For example:

A Middleman Attack can compromise your online accounts and identity. If an attacker intercepts your login credentials or personal information, they can access your email, social media, online banking, or other services. They can also pretend to be you and send messages on your behalf, which can ruin your reputation or relationships.
A Middleman Attack can expose your confidential data and transactions. If an attacker intercepts your online payments or transfers, they can steal your money or credit card details. They can also access your sensitive documents or files, such as medical records, tax returns, or business contracts.
A Middleman Attack can infect your devices and networks with malware. If an attacker inserts malicious code or links into your communications, they can infect your devices with viruses, ransomware, spyware, or other malware. They can also use your devices as part of a botnet or launch further attacks on other targets such as DDoS attack.

How Middleman Attacks Work

A Middleman Attack can be divided into two phases: interception and manipulation.

Interception

In this phase, the attacker establishes a connection with both the client and the server and makes them believe that they are communicating with each other directly. The attacker can use different methods to achieve this:

ARP spoofing

The attacker links their MAC address with the IP address of the server on the local network. When the client sends an ARP request to find out the IP address of the server, the attacker responds with their own MAC address. This way, the client sends all their traffic to the attacker instead of the server.

DNS poisoning

The attacker changes the website address record on the DNS server or the client’s device. When the client requests the IP address of a website, such as www.example.com, the attacker returns their own IP address instead of the legitimate one. This way, the client connects to the attacker’s website instead of the real one.

ICMP packet spoofing

The attacker sends ICMP redirect packets to both the client and the server. These packets tell them that there is a better route for their communications through the attacker’s device. This way, the client and the server route all their traffic through the attacker instead of directly.

SSL stripping

The attacker downgrades the HTTPS connection between the client and the server to HTTP. This removes the encryption and authentication layers that protect the communications from eavesdropping and tampering. The attacker can then intercept and modify the plain text messages.

Manipulation

In this phase, the attacker performs various actions on the intercepted communications, such as:

Eavesdropping

The attacker listens to the messages and extracts any valuable information, such as passwords, credit card numbers, or personal data.

Altering

The attacker changes the content or format of the messages, such as adding, deleting, or replacing words, numbers, or symbols.

Injecting

The attacker inserts new messages or data into the communications, such as malicious code, links, or commands.

Blocking

The attacker prevents some or all messages from reaching their destination, such as deleting, delaying, or dropping them.

The attacker can perform these actions in real time or store the messages for later use. The client and the server are unaware of the attacker’s presence and actions, as they receive seemingly normal and valid responses.

How to avoid Middleman Attacks

A Middleman Attack can be difficult to detect and prevent, as it exploits the weaknesses of the network protocols and devices. However, there are some best practices and tools that can help you avoid MITM attacks. Here are some of them:

Use HTTPS websites

HTTPS websites use SSL/TLS encryption and certificates to secure the communications between the client and the server. This prevents the attacker from intercepting or modifying the messages. You can check if a website is HTTPS by looking for a padlock icon or a green address bar in your browser. You can also use browser extensions such as HTTPS Everywhere to force HTTPS connections on all websites.

Avoid public Wi-Fi networks

Public Wi-Fi networks are often unsecured and easy to intercept by attackers. If you have to use them, make sure to use a VPN (Virtual Private Network) service that encrypts your traffic and hides your IP address. You can also use a personal hotspot from your mobile device instead of a public Wi-Fi network.

Update your devices and software

Outdated devices and software may have security flaws that can be exploited by attackers. Make sure to update your devices and software regularly with the latest patches and fixes. You can also use antivirus and firewall software to scan your devices for malware and block any suspicious traffic.

Verify the identity of the sender

Before opening any email, message, or link, make sure to verify the identity of the sender. You can do this by checking their email address, phone number, or social media profile. You can also contact them directly through another channel to confirm their message. Do not click on any links or attachments that look suspicious or ask for your personal information.

Use two-factor authentication

Two-factor authentication (2FA) adds an extra layer of security to your online accounts. It requires you to enter a code or a token that is sent to your phone or email after entering your password. This prevents the attacker from accessing your account even if they have your password.

Conclusion

A Middleman Attack is a serious cyberthreat that can compromise your online privacy, security, and reputation. It involves an attacker intercepting and manipulating the communication between two parties who trust each other.

To avoid Middleman Attacks, you should use HTTPS websites, avoid public Wi-Fi networks, update your devices and software, verify the identity of the sender, and use two-factor authentication. It is also recommended to use tools such as VPNs, antivirus software, and browser extensions that can help you encrypt your traffic and detect any malicious activity.