Man-in-the-Middle (MITM) attacks are one of the most stealthy attack types out there. These attacks are crafty, sophisticated, and can wreak havoc on your organization’s data and trust. This type of attack poses all the usual data loss risks, as well as the potential for competitors to have ongoing access to industry sensitive information.
In this article, we’ll break down what Man-in-the-Middle attacks are, the way they work, and the things that IT managers in SMBs should be doing to protect their organization. Man-in-the-Middle attacks aren’t just something you need to know about, it’s something you need to plan for.
The scariest part of this attack is that you might not even notice that it’s happening. That’s because a Man-in-the-Middle attack is when your communications are intercepted whilst in transit. This means that the information can be read by a third-party, before it is sent on to the recipient. This digital hijacking can lead to financial loss, data breaches, and reputational damage.
Did you know that nearly 58% of all posts on criminal market places and forums contain banking data collected in attacks like MITM attacks.
Read on as we explore what a Man-in-the-Middle attack is, why it’s so dangerous, and how you can protect your organization.
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What is a Man-in-the-Middle Attack?
Let’s start with the basics.
A Man-in-the-Middle attack occurs when a cybercriminal intercepts and potentially alters the communication between two parties who believe they’re communicating directly with each other. This can be as straight forward as text communication between two people or involve the ways that computer systems convey information and data from your device, to the services you use.
Think of it as an eavesdropper who not only listens to your conversation but can also manipulate what’s being said.
In an MitM attack, the attacker positions themselves between the victim and their intended destination—such as a website, email server, or another user. They can steal sensitive information like login credentials, financial details, or proprietary data, or even inject malicious content.
In this case, the victim might not only be the individual who is having their data monitored, but the intended destination for that data. Often, the identity that is being impersonated.
The scariest part? Both parties often have no idea the attacker is there.
What makes MitM attacks so harmful is their stealth and versatility. They can target emails, web browsing, or even IoT devices.
Approximately 19% of successful attacks are man in the middle attacks, with weak encryption practices responsible for nearly 70% of successful attacks within the US.
What does it look like?
This is the tricky part.
If you or your organization falls victim to an MitM attack, it might not be immediately obvious.
You might notice unusual login attempts, corrupted data, or unexpected redirects when accessing websites. For example, employees might see a fake login page that looks legitimate but captures their credentials. In some cases, communications might be altered—think an email instructing a payment to a fraudulent account.
Attackers may not announce their presence as they would in a ransomware attack. Instead, it’s in their interest to stay undetected, accessing your data and information without letting you know.
You might only realize you’ve been hit when customers report unauthorized charges or sensitive data appears on the dark web. Even when this does happen, it may not be immediately obvious how the attack has occurred and where the vulnerability is.
How Does a Man-in-the-Middle Attack Work?
So, there are several main types of man-in-the-middle attacks, each exploiting a different part of your network.
- There’s email hijacking which gives malicious actors access to confidential correspondence, ideally from a bank or some other trusted institution.
- There’s wi-fi eavesdropping where victims will log on to a legitimate sounding wi-fi network, only to have all of their activity logged and monitored. This is particularly relevant to users who work out of office and might be encouraged to log into a “Free Wi-Fi Network”.
- DNS Spoofing stands for Domain Name System Spoofing and involves legitimate traffic being redirected to malicious sites masquerading as the real thing.
- An adjacent method is IP Spoofing – this is where specifically internet traffic is diverted to a fraudulent site.
- SSL hijacking is where the attacker intercepts traffic between the server and the user’s computer via the Secure Socket Layer.
- Some methods are more technical – ARP Cache Poisoning involves the system that computers use to communicate with different services. The victim’s device is tricked to send information via the malicious actor, rather than via the genuine gateway.
- There’s session hijacking which is more of a waiting game. The attacker waits for the user to log into an application – perhaps a banking app – then steals the session cookie, allowing the malicious actor access to these services.
- Attackers can also steal browser cookies – sometimes called HTTP cookies. This works in a very similar way to session hijacking, but allows attackers to access information stored as cookies – this is often the information that autofills to save you time.
As with many of these attack categories, you don’t need to know the specific details of every variation. It is more important to be aware of the creative approach that attackers take, and that they will exploit any opportunity that arises.
It is also worth considering which hat you are wearing, to understand which attacks you might be susceptible to. Wi-Fi eavesdropping is more likely to happen when you are travelling and looking to log into unknown Wi-Fi networks. As an IT Manager, you’ll need to ensure that employees are aware of this type of attack, but it is not one that you need to implement specific policies to address.
Once the attacker is “in the middle,” they can monitor, steal, or alter data in real-time.
For example, in a banking MitM attack, they might change the recipient’s account details during a transaction. The speed and invisibility of these attacks make them particularly dangerous.
In 2024, MitM attacks exploiting public Wi-Fi networks rose by 22%, with attackers increasingly targeting remote workers.
How to Stop Man-in-the-Middle Attacks
So, how can your organization protect itself before an MitM attack strikes?
VPNs – Virtual Private Networks – can be a great asset in defending against these attacks. VPNs operate like an encrypted tunnel that prevents anyone other than the recipient from accessing the data – essentially cutting out anyone in the middle trying to snoop on your data.
Expert Insights have put together a shortlist of the top enterprise VPNs to help you find the best one for your needs. Check out expertinsights.com for more information.
Beyond using VPNs, we have got six strategies that you should look to implementing. They fall into two main categories – better monitoring, and better user practices.
- Use Encrypted Connections: Always use HTTPS for websites and enforce end-to-end encryption for emails and communications.
- Implement Strong Authentication: Use multi-factor authentication (MFA) to add an extra layer of security. Even if credentials are intercepted, attackers can’t access accounts without the second authentication factor.
- Employee Training: Educate staff to recognize phishing emails, fake Wi-Fi networks, and suspicious login pages. This can be as straightforward as keeping them up-to-date on attack techniques and telling them not to log in to unknown Wi-Fi networks. You should conduct simulations to test their ability to spot MitM tactics.
- Secure Your DNS: Deploy DNS security solutions like DNSSEC to prevent DNS spoofing. Regularly monitor DNS traffic for suspicious activity.
- Keep Software Updated: Patch vulnerabilities promptly, as attackers often exploit outdated software or unpatched systems, as seen in the Equifax breach. Use automated patch management tools to stay current.
- Monitor Network Traffic: Deploy Intrusion Detection Systems to spot unusual patterns, like unexpected redirects or unauthorized devices on your network. Regular audits can catch MitM attempts early.
Conclusion
Man-in-the-Middle attacks are an often overlooked threat as they’re not big and flashy. They’re subtle. There’s hiding in the shadows. But they are happening.
By understanding how they work and implementing strong defenses—encryption, MFA, DNS security, training, updates, and monitoring—you can protect your organization.
