Decrypting Man-in-the-Middle Attacks

What if an intruder has access to all of your highly confidential data? With that much data, how much damage can they cause your organization? 

This is what unfolds during a man-in-the-middle cyberattack, a data breach with few warning signs. Read ahead to know further details. 

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

A man-in-the-middle (MITM) attack happens when an attacker secretly positions themselves between two parties. From that position, the attacker can:

• Eavesdrop on the conversation and the data exchanged
• Steal credentials, card details, and other sensitive data
• Alter messages in transit without either side noticing

During a man-in-the-middle attack, everything looks seemingly normal. Pages load, messages send, and nothing seems wrong. Victims often learn about the attack only after money or data is transferred. This normality is dangerous, since what cannot be detected cannot be prevented.

ER Tech Pros works overtime to improve anomaly detection in your business systems. Our comprehensive services ensure your organization remains fully protected against these vulnerabilities.

How Does a Man-in-the-Middle Attack Work?

Every online interaction involves a chain of trusted connections. Your device trusts the network, the network trusts DNS to resolve the correct server, and the server's certificate verifies its identity. A MITM attack works by secretly breaking or exploiting any one link in that chain, rather than hacking a device to exercise frontless control.

Once the attacker compromises a link in the path, any traffic flows through it before reaching its destination. The attacker can copy it or modify it along the way. Both sides keep receiving responses, so neither suspects anything. The attack may last seconds or run for months.

Stages of a Man-in-the-Middle Attack

Most MITM attacks follow two main stages.

1. Interception

The attacker compromises a communication path. This could mean setting up an infected Wi-Fi hotspot, poisoning a local network, or tampering with DNS responses. The goal is to control your data and traffic for an MITM attack.

2. Decryption or Manipulation

Much of today's traffic is encrypted, so simply intercepting it offers little. The attacker must defeat the protection. Attackers can do this by downgrading a secure connection, presenting a fake certificate, or stealing a session token after a user logs in. 

Once they gain access, they can read and steal data, or inject changes such as altered payment details or installed keyloggers to access more data. Some attackers also cover their tracks to maintain access, allowing them to return later for more.

Man-in-the-Middle Attack Techniques

These are some of the methods attackers use to intercept and decrypt traffic for MITM attacks.

• ARP Spoofing

The Address Resolution Protocol (ARP) links an IP address to its corresponding Media Access Control (MAC) address within a local network. The attacker spoofs the target's ARP responses to associate the target's IP address with the attacker's MAC address. Traffic then flows through the attacker.

• DNS Spoofing 

The Domain Name System (DNS) links domain names to their designated IP addresses. By corrupting DNS responses, attackers redirect you from a legitimate website to a fake lookalike, even when you type the correct address. 

• SSL Stripping

This method targets sites that receive incoming HTTP traffic before rerouting it to secure HTTPS connections. MITM threat actors intercept this transition, capturing unencrypted information before it is sent over the protected HTTPS link. This lets them read the data in plain text, compromising confidentiality.

• IP Spoofing

Online entities, including websites, network devices, and email addresses, are identified by Internet Protocol (IP) addresses. MITM attackers manipulate or falsify these addresses to disguise a malicious source as a trusted host, deceiving users into connecting with it.

Common Man-in-the-Middle Attack Types

Attackers combine the techniques described above into several recognizable MITM attack types. Some of them are: 

• Fake Wi-Fi and Hotspots

An attacker sets up a free Wi-Fi hotspot in a public place, such as a park, an airport, or a restaurant, with a convincing name like "Airport_Free_WiFi." Anyone who connects to it sends all their traffic through the attacker's device. The attacker can harvest all confidential information, such as usernames, passwords, credit card numbers, and other personally identifiable information. 

• Email Hijacking 

Attackers who gain access to an email account quietly monitor conversations, then step in at the right moment, for example, to swap bank details on an invoice. This is a common route to business email compromise. The most common targets are banks or credit Card companies.

• Session Hijacking and Cookie Theft

Browsers temporarily store session details in cookies during web communications. MITM threat actors intercept these cookies to hijack sessions or extract sensitive credentials, such as account passwords and credit card numbers.

Because session cookies expire quickly, attackers must use the stolen data before it becomes invalid.

Attackers use these methods for credential theft, payment fraud, corporate espionage, surveillance, and injecting malware into otherwise legitimate downloads.

Preventing Man-in-the-Middle Attacks

Individuals and organizations can do a few things to prevent man-in-the-middle attacks. Some of these are listed below:

• Never ignore browser warnings about invalid or untrusted certificates.
• Websites that have a missing padlock or ‘Not secure’ label should be avoided.
• Employ reliable VoIP security to avoid eavesdropping on voice traffic.  
• Unexpected redirects on websites or pages that look slightly off are suspicious.
• Avoid unfamiliar or duplicate Wi-Fi networks with similar names. 
• Sudden logouts or unexplained session drops are also suspicious. 
• Never click through a certificate warning. It is often the only visible clue.
• Consider employing a high-quality firewall-as-a-service for your digital infrastructure. 
• Use multi-factor authentication to verify payment changes through a second channel.

• Use endpoint protection to catch man-in-the-browser malware.

Take Complete Control of Your Digital Security

MITM attacks succeed by exploiting trust in networks and websites, and the assumption that a connection is private. A few habits shut down the vast majority of these attacks. 

For long-term, holistic protection, choose a strong cybersecurity services partner. ER Tech Pros provides comprehensive cybersecurity services to protect your organization from a wide range of attacks.