Attackers are shifting tactics to target the data moving between users and the systems they trust. IBM’s 2025 Cost of a Data Breach Report found that phishing was involved in 16% of breaches, continuing its history of being one of the most common entry points. One attack that builds on phishing and unsafe networks is the man-in-the-middle attack (MITM), a threat best understood to better protect against.
What Is a Man-in-the-Middle (MITM) Attack?
A man-in-the-middle (MITM) attack is a type of cyberattack in which an attacker intercepts and controls the flow of data between two parties without their knowledge. They can read, capture, or change the data being sent. That creates an opening to steal sensitive information such as passwords or session tokens. In some cases, stolen tokens allow attackers to bypass MFA and access accounts. MITM attacks often start with phishing emails or unsafe public Wi-Fi.
How a MITM Attack Works
A man-in-the-middle attack begins when an attacker inserts themselves into the data flow between two systems. That is also known as an on-path attack. The victims believe they have a secure connection, but the attacker is intercepting it. This allows them to capture, read, or even modify sensitive data, such as logins, tokens, or financial details.
How Attackers Gain Access
Attackers need a way to insert themselves into the flow of traffic. Common methods include:
- Phishing emails with fake links that trick users into entering login details.
- Setting up a rogue wireless access point in a public space.
- Exploiting network vulnerabilities to redirect traffic.
- Using a packet sniffer to capture unprotected communication.
Breaking Security Protections
Even when traffic is encrypted, attackers continue to look for ways around it. They may:
- Present a fake SSL certificate to break an SSL connection and trick the browser into allowing insecure communication.
- Attempt decryption if weak encryption keys are used.
- Use code injection to alter pages or scripts and capture login details.
What Attackers Can Steal
Once in place, attackers can capture more than just passwords. Targets include:
- Browser cookies that keep users logged in.
- Session tokens that bypass the need for re-entering credentials.
- Sensitive data shared over insecure communication channels.
When attackers gain access to tokens or cookies, they can launch a session hijacking attack. That lets them log into services without triggering another MFA prompt, making token theft one of the most damaging outcomes of an MITM attack.
Common Types of MITM Attacks
MITM attacks can take many different forms. Some focus on tricking users, while others exploit weaknesses in networks or encryption. Below are some of the most common methods attackers use to steal data and gain access.
Phishing and Email Hijacking
Phishing is one of the most common starting points. A fake email tricks users into clicking a link or entering login details. In more advanced cases, email hijacking follows. Attackers take over a mailbox and quietly read or change messages.
Wi-Fi Exploits
Public Wi-Fi often lacks strong protection. Wi-Fi eavesdropping lets attackers capture traffic that is not encrypted. An evil twin attack goes further. A fake hotspot looks legitimate, but every action passes through the attacker’s system.
Network Spoofing
MITM attacks often depend on rerouting traffic. In ARP spoofing, attackers send false messages in a network to redirect data. IP spoofing disguises an attacker’s address to look trusted. Both methods enable credential sniffing and theft of private data.
Session and Browser Hijacking
Stolen cookies or tokens allow session hijacking. Attackers log in without re-entering passwords or triggering MFA. A man-in-the-browser attack goes even deeper. Malware inside the browser captures or changes data before it leaves the device.
Attackers also use adversary-in-the-middle (AiTM) phishing. These campaigns proxy the real login page, capture credentials, and steal the session cookie at the same time. That enables “pass-the-cookie” token replay, giving attackers account access even when MFA is used.
DNS Manipulation
DNS spoofing alters how a device resolves website addresses. Instead of reaching the real site, the victim lands on a fake one. Attackers use this to steal logins, credit card details, or other information.
SSL/TLS Attacks
Encryption should protect traffic, but attackers can weaken it. SSL stripping downgrades a secure HTTPS session into an unencrypted HTTP. SSL/TLS hijacking works differently. Here, attackers use a fake SSL certificate to break a trusted SSL connection and view sensitive data.
What Industries or Users Are Vulnerable to MITM Attacks?
No industry is completely safe from MITM attacks, but some face greater exposure than others. Weak technology, risky user behavior, and poor security controls provide attackers with easy entry points. The areas below highlight where these vulnerabilities are most commonly found.
- Financial applications that process sensitive payments and account details.
- Small and midsize businesses with limited IT resources and monitoring.
- Industrial networks that support manufacturing and critical infrastructure.
- IoT devices with poor encryption or outdated software.
- Mobile devices on unsecured Wi-Fi connections or other unencrypted communication.
- Web applications with framework flaws or weak session management.
- Systems with poor endpoint security or mishandled public/private keys.
- Unmanaged or personal devices that fall outside corporate visibility and controls.
MITM risk often increases when convenience is prioritized over security. Mobile devices on public Wi-Fi are an easy entry point. IoT devices increase the risk since many ship with weak security protections and rarely receive updates. Small businesses face greater exposure because they often lack strict controls, trained staff, or strong monitoring.
Larger organizations are not immune. Financial firms are high-value targets because stolen account data can be used right away. Healthcare providers face equal danger, since medical records and patient details sell for high prices on the dark web.
Manufacturers and industrial operators also remain vulnerable. Attacks on industrial networks can disrupt production, safety systems, or even critical infrastructure. Across all industries, weak encryption and poor session management leave sensitive data exposed. That’s why understanding these risks is a key part of preventing them.
Tools Often Used By Hackers in Man-in-the-Middle Attacks
Hackers often employ malware and automated tools when conducting MITM attacks. One example is TrickBot, which included a module called shaDll. It installed fake SSL certificates, redirected traffic, and captured sensitive data. Attackers also utilize data capture tools, such as packet sniffers, proxy frameworks, and phishing kits, to steal logins and session tokens.
Security teams rely on many of the same methods for defense and testing. Web vulnerability assessments and manual penetration testing help uncover weaknesses before they can be exploited. Endpoint security, combined with updated antivirus software, blocks malicious modules, while quick security patches close known vulnerabilities. Modern security analytics and machine learning tools add another layer by spotting unusual activity that may signal an MITM attack.
What a Microsoft MITM Attack Can Look Like
A common MITM attack against Microsoft accounts begins with a phishing email. The email links to a fake login site designed to look like Microsoft’s sign-in page. To the user, nothing seems suspicious. They enter their email, password, and even approve the session via multi-factor authentication (MFA).
Behind the scenes, the attacker collects both the credentials and the MFA-approved session token. With that token, they can sign in as the user without triggering another MFA prompt. Once inside, they gain full access to the account. They can read email, download files, or change the password to lock out the rightful owner.
The difference between the fake and real sites is easy to miss. The fake page uses a lookalike domain name, while the real Microsoft login always uses login.microsoftonline.com. Checking the URL is one of the most effective defenses. This example illustrates how a MITM attack can steal a password and hijack the login session, even when MFA is enabled. As a result, it’s important to remember that not all MFA is phishing-resistant.
Other Real-World Examples of an MITM Attack
Man-in-the-middle attacks have been reported in both real-world incidents and security studies. The following examples highlight how attackers intercept data and why these methods remain a serious risk.
DigiNotar Certificate Breach
Attackers broke into the Dutch certificate authority DigiNotar and issued fraudulent SSL certificates. Those certificates were then used in man-in-the-middle attacks to intercept encrypted traffic, including Gmail accounts. The breach forced browsers to block DigiNotar certificates, showing how a single trusted provider can compromise global data transfers.
Lenovo Superfish Adware
Several Lenovo laptops shipped with Superfish adware that installed a universal root certificate. That made it possible to intercept HTTPS traffic directly on the device. The case revealed how weak endpoint security and vendor-installed software can create MITM risks before a business even deploys its hardware.
SS7 Mobile Interception
Ongoing studies have long demonstrated weaknesses in the SS7 telecom protocol. These flaws allow attackers to intercept calls and text messages across mobile networks. In practice, this means SMS-based MFA codes can be stolen or redirected. The findings show why relying on SMS for authentication leaves accounts exposed to network-level man-in-the-middle attacks.
How to Defend Your Business Against MITM Attacks
Protecting against MITM attacks means using several layers of security. The most effective layer is user awareness. Employees should verify the URL before entering credentials to ensure it’s the correct website. They should also avoid entering credentials on public or unencrypted Wi-Fi. Training staff to recognize phishing and unsafe sites can prevent many attacks early.
Access controls provide the next layer of defense. Conditional access policies can block risky logins, such as attempts from outside the country, and shorten the life of MFA tokens. Businesses should also adopt phishing-resistant MFA. FIDO-compliant options, such as Windows Hello or hardware tokens like YubiKey, verify a device’s presence, making it far harder for attackers to reuse stolen credentials. Device-bound tokens, such as Microsoft’s Token Protection, go further by tying tokens to the device that requested them.
Technical measures add another layer of protection. Secure SSL/TLS configuration, routine patching, and zero-trust policies close common weak points. Endpoint security, including advanced threat protection and updated antivirus software, further reduces the risk. And continuous monitoring with security analytics and threat intelligence helps detect unusual activity early.
Detection and Response
Finding token theft requires strong visibility into sign-ins. Microsoft Entra ID can alert on anomalous token use, impossible travel, and repeated suspicious logins. High-severity alerts tied to privileged users should be investigated quickly.
When a token is stolen, revoke refresh tokens to force reauthentication. Continuous Access Evaluation reduces how long access tokens stay valid. After eviction, reset passwords and review for persistence. Look for mailbox rules, auto-forwarding, new MFA methods, rogue device enrollment, or external file sharing.
MITM Attack Security Checklist
- Train users on phishing and safe browsing habits.
- Enforce conditional access policies to block risky logins.
- Use phishing-resistant MFA with FIDO-compliant options.
- Apply patches quickly and secure SSL/TLS use.
- Adopt zero-trust access controls and strong endpoint security.
- Monitor traffic with security analytics and threat intelligence.
By combining user awareness, access controls, and technical safeguards, businesses build a stronger defense. Each layer adds protection, making an MITM attack much harder to carry out.
Stop Man-in-the-Middle Attacks Before They Disrupt Your Business
MITM attacks can steal data and hijack accounts, putting daily operations at risk. Stopping them takes trained users and defenses that work together at every layer. ITonDemand delivers managed cybersecurity services built to close those gaps. We secure configurations, monitor for suspicious activity, train users, and give businesses the support they need. With ITonDemand, you can stay ahead of threats that turn trusted connections into open doors.
