What is a Man in the Middle (MitM) Attack: Examples & Prevention Methods

In the realm of cyber threats, a Man in the Middle (MITM) attack is an insidious technique that poses a serious threat to online security as the attacker intercepts the communication between the victim and the entity being impersonated. It has serious consequences such as the theft of sensitive information and the use of MITM attacks to inject malware into legitimate traffic, which can then infect the victim’s system.

In simple terms, a Man In The Middle attack is a type of cyber attack where the perpetrator inserts himself into a conversation between two parties. The ultimate goal of an attacker is to steal sensitive information, such as login credentials, account details, and payment card numbers.

MITM attacks target users of financial applications, SaaS businesses, e-commerce sites, and websites where logging in is required. Attackers will use a range of methods to carry out the attack, such as setting up malicious Wi-Fi hot spots or using DNS spoofing techniques.

The most common way to detect an MITM attack is by noticing abnormal behavior on devices that are connected to the network. For example, a sudden slowdown in connection speeds or an increased number of network requests can indicate that something is amiss. Other signs could include pop-ups asking for additional authentication or passwords when logging in to a website.

What is a Man in the Middle (MITM) attack?

An MITM attack occurs when a malicious actor intercepts communication between two parties. This could be between a user and a financial application, an e-commerce site, or any website requiring login credentials. The attacker can then eavesdrop or even impersonate one party to steal sensitive data.

How do MITM attacks happen?

Typically, MITM attacks happen in two stages. Firstly, the attacker must intercept the user’s data. Cybercriminals can do so through malware, Wi-Fi eavesdropping, or IP spoofing. Secondly, the attacker must decrypt this data if it’s encrypted.

Stage One: Interception

The first stage of an MITM attack involves intercepting the user’s data.

• Malware: Attackers can introduce malware into a user’s device, which then acts as a gateway for them to intercept data. This malware can come from malicious downloads, email attachments, or infected websites.
• Wi-Fi Eavesdropping: If a user connects to an insecure or compromised network, attackers can eavesdrop on data transmission. Public Wi-Fi networks are particularly vulnerable to this type of interception.
• IP Spoofing: Attackers may also engage in IP spoofing, where they manipulate IP address information to impersonate a trusted network or device. This can trick users into sending data directly to the attacker.

Stage Two: Decryption

If the intercepted data is encrypted, the attacker must then decrypt it to gain access to the information.

• Key Cracking: Attackers may use brute force or more sophisticated methods to crack the encryption key. As soon as the key is compromised, the attacker can decrypt the intercepted data.
• Protocol Vulnerabilities: In certain scenarios, attackers may exploit vulnerabilities in the encryption protocols to decrypt the data. This is why keeping software and security protocols up-to-date is essential to prevent MITM attacks.

Types of Man in the Middle (MITM) attacks

Man-in-the-middle (MITM) attacks are a common type of cybersecurity attack that allows attackers to eavesdrop on the communication between two targets.

The attackers can place themselves at any point along the communication chain to carry out this type of cyber attack.

Impersonation

The attacker imitates the look of a legitimate application, website, or service to intercept data. The user may not even realize they’re interacting with an imposter.

For instance, the attacker could pretend to be a financial application, prompting the user to enter their login credentials. In the process, these credentials are captured by the attacker.

IP Spoofing

In this type of attack, the attacker spoofs the IP address of a legitimate user to intercept and modify data packets.

Attackers manipulate the ARP (Address Resolution Protocol) cache of a target device to redirect its network traffic through their own devices, enabling them to intercept and manipulate the communication.

DNS Spoofing

In DNS spoofing, the perpetrator redirects traffic from the legitimate site or application to a malicious one, which looks exactly like the original site. They redirect the user to a fake website by modifying the DNS server’s address resolution protocol.

HTTPS Spoofing

HTTPS spoofing is a type of attack where the attacker intercepts the encrypted communication between two parties and decrypts it to read the data.

Attackers use network sniffing tools to capture and analyze network traffic, allowing them to intercept sensitive information.

Email Hijacking

In email hijacking, the attacker intercepts email messages and alters them before forwarding them to the recipient. Attackers inject malicious packets into the communication stream to alter or manipulate the data being transmitted.

This can potentially cause damaging miscommunication.

Wi-Fi Eavesdropping

In this type of attack, the attacker intercepts data packets transmitted over an unsecured Wi-Fi network. They can also set up a fake Wi-Fi access point to trick users into connecting to it, allowing them to intercept and manipulate their traffic.

Session Hijacking

In session hijacking, the attacker steals the session ID of a user and uses it to impersonate the user.

How to prevent MITM attacks

Defending against Man In The Middle attacks involves a multi-faceted approach.

Users should ensure they are connected to a secure network, particularly when accessing sensitive data. Avoid using public Wi-Fi networks for sensitive transactions, as attackers can easily set up rogue hotspots.

Also, always use HTTPS for online transactions. HTTPS encrypts the communication between the user and the website, thereby preventing an attacker from reading or modifying any data sent during the session.

Method 1: Encryption

Prefer encrypted connections (HTTPS) for any sensitive online activity.

Encryption plays a crucial role in safeguarding data from MITM attacks. It involves converting information into an unreadable format for unauthorized users. Two types of encryption are commonly used: symmetric and asymmetric.

Symmetric encryption uses a single key for encryption and decryption, while asymmetric encryption uses different keys for each.

Secure Sockets Layer (SSL) and Transport Layer Security (TLS) are protocols for establishing encrypted links between networked computers, helping to ensure that all data passed between parties remains private and secure. Adopting these encryption methods can significantly reduce the likelihood of an MITM attack.

Method 2: Secure networks

Avoid using public Wi-Fi for transactions or accessing sensitive data.

Public Wi-Fi networks are a major target for MITM attacks. By using secure, private connections, you can greatly reduce the risk of interception and impersonation.

Additionally, it’s important to be aware of phishing attempts when providing personal information. Make sure to verify the legitimacy of websites or emails before providing any sensitive data.

Method 3: Multi-factor authentication

Add an extra layer of security by implementing multi-factor authentication (MFA).

MFA requires a user to provide two or more verification methods to gain access to a resource such as an application or online account. This multi-layered approach ensures that even if an attacker manages to steal one authentication factor, they will still be unable to access the resource without additional factors.

Method 4: Regular software updates

Ensure your system is always up-to-date.

Software updates often include patches for security vulnerabilities that might be exploited by attackers.

By regularly updating your software, you’re reducing the chances of falling victim to an MITM attack. This applies not only to your operating system but also to the software on your system.

Authentication-in-the-Middle

Authentication-in-the-middle (AiTM) is a phishing technique that exploits the growing use of multi-factor authentication (MFA). While similar to the classic Man-in-the-Middle (MitM) attack, AiTM specifically targets the MFA process to bypass this security measure.

How it works

1. Phony Login: Attackers create a fake website that mimics a legitimate login page (e.g., your bank).
2. Credentials Captured: Unsuspecting users enter their login credentials on the fake site.
3. Transparent Relay: The fake site relays these stolen credentials to the real website, often in real time.
4. MFA Interception: The user completes the MFA step on the fake site, unknowingly providing the code to the attackers.
5. Full Account Access: With login details and the MFA code, attackers gain complete control of the compromised account.

Similarities to MitM

Both AiTM and MitM intercept communication between a user and a legitimate website. They aim to steal sensitive information like usernames, passwords, and authentication codes.

Differences from MitM

Unlike MitM attacks that can target any data transfer (emails, file downloads, etc.), AiTM specifically targets the MFA process. MitM attacks often require technical expertise to intercept network traffic, while AiTM relies on social engineering to trick users into revealing their credentials on a fake website. This makes AiTM potentially more widespread as it requires less technical knowledge from the attacker.

Preventing AiTM

• Be Wary of Links: Don’t click on links from suspicious sources, even in sponsored search results. Phishing emails or messages often contain malicious links that can lead to fake login pages.
• Check URLs: Always double-check the website address before entering your login information. Legitimate website addresses should use HTTPS and have a valid security certificate. Look for any typos or inconsistencies in the URL that might indicate a fake website.
• Use Security Software: Security software with anti-phishing features can help block access to known phishing websites. While not foolproof, security software can add an extra layer of protection.

Consider Passkeys: Passkeys are a new and more secure alternative to traditional MFA codes. Passkeys are generated and stored on your device and don’t require entering a code on every login. Since AiTM relies on stealing the MFA code, it wouldn’t be effective against passkeys.

Secure your networks and systems 

SalvageData is a leading expert in data recovery and protection. We can help businesses secure their networks and implement best practices to avoid falling victim to MITM attacks. Our services include regular security audits, network security solutions, and employee education programs to promote a culture of cybersecurity awareness in your organization.

Contact us 24/7 for emergency data recovery services. Our ransomware removal experts can help you mitigate the Man In The Middle attack and prevent future attacks.