While the nature of cyberattacks is constantly changing, and our lives become more and more influenced – if not affected – by global health problems, thus leaving our cybersecurity even more vulnerable, information remains the most powerful tool we have. When it comes to the cybersecurity of your business, the so-called man-in-the-middle attack is one of the threats you must be aware of. 

The three players involved in a man-in-the-middle attack are the victim, the entity with which he or she is trying to communicate and the man-in-the-middle, intercepting the victim’s communication. Essential to the success of this kind of attack is that the victim isn’t aware of the man in the middle.

In other words, during a man-in-the-middle attack, a malicious player inserts him/herself into a conversation between two parties, impersonates both of them and gains access to the information that the two parties were trying to share. The malicious player intercepts, sends and receives data meant for someone else – or not meant to be sent at all, without either outside party knowing until it’s already too late. You might find the man-in-the-middle attack abbreviated in various ways: MITM, MitM, MiM or MIM. 

man-in-the-middle attack flow illustration

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Public Wi-Fi networks are most likely to be used during a man-in-the-middle attack because they usually are less secure than private Internet connections. Criminals get in the middle by compromising the Internet router, by scanning for unpatched flaws or other vulnerabilities. The next step is to intercept and decrypt the victim’s transmitted data using various techniques – about which we will tell you more below.  The most susceptible for a man-in-the-middle attack are the financial sites, other sites that require a login and any connection meant to be secured by a public or private key. 

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A man-in-the-middle attack can come in many shapes, yet the most common are the following: 

1. IP spoofing 

The Internet Protocol Address (IP) refers to a numerical label which is assigned to each device that connects to a computer network that uses the Internet Protocol for communication. IP addresses have two main functions: host or network interface identification and location addressing. By spoofing an IT address, attackers make you think that you’re interacting with a website or someone you’re not, thus allowing the attacker access to the information you’d otherwise keep to yourself.  

2. HTTPS spoofing 

The HyperText Transfer Protocol (HTTP) represents the foundation of data communication for the World Wide Web, hypertext documents including hyperlinks to other resources that users can access. HTTPS means that a particular website is secure and can be trusted. Despite that, attackers can fool your browser into believing it’s visiting a trusted website when it’s not. 

3. DNS Spoofing

The Domain Name System (DNS) is a hierarchical and decentralized naming system for computers, services or other connected to the Internet resources, which translates more readily memorized domain names to the numerical IP addresses needed for localization and identification. By DNS spoofing, an attacker’s goal is to divert traffic from a real website or capture user login credentials, trying to force you to access a fake one. 

4. SSL hijacking 

SSL stands for Secure Sockets Layers and is a type of protocol that establishes encrypted links between your browser and the webserver. A connection to a secure server (guaranteed by HTTPS) means that standard security protocols are in place, protecting whatever data you’re sharing to that server. When someone hijacks SSL, he/she uses another computer and another secure server to intercept all the information passing between the server and the user’s computer. 

5. E-mail hijacking

E-mail hijacking is a type of man-in-the-middle attack used by cybercriminals to target e-mail accounts of banks or other financial institutions. After they have obtained access, they could monitor transactions between an institution and its customers and convince them to follow the attacker’s instructions, and not the bank’s. The result? If you’re not paying enough attention, you may end up putting your money in the attacker’s pockets. 

6. Stealing browser cookies 

In technical language, cookies are small pieces of information – like items you add in the cart of an online store – that websites store on your computer. Since browser cookies can store passwords, addresses and various other types of sensitive information, they can become the target of cybercriminals. 

7. Wi-Fi eavesdropping 

This type of man-in-the-middle attack is particularly dangerous: hackers can set up Wi-Fi connections that sound very legitimate, similar to a business you know. Once a user connects to it, the cybercriminal will be able to monitor its online activity and intercept login credentials, payment card information etc.  A man-in-the-middle attack is dangerous. End users can carry on with their business for days or even weeks without noticing that something is wrong. Consequently, it’s almost impossible to know, during that time, what data was exposed to malicious actors. Finding out more about what happened often requires good knowledge of the internet or mobile communication protocol and security practices.  Fortunately, there are some security measures you can take in order to be safe. 

Here are some precautions that may help you to avoid a man-in-the-middle attack: 

1. Use a VPN 

A Virtual Private Network (VPN) is used to extend a private network across a public one, enabling users to share and receive data as if their devices were directly connected to that private network. Particularly useful when talking about preventing a man-in-the-middle attack is that VPN connections can mask your IP address by bouncing it through a private server. Plus, they can encrypt the data as it’s transmitted over the Internet. 

2. Access only HTTPS websites 

HTTPS websites prevent attackers from intercepting communications by encrypting data.  An excellent method to go around HTTPS spoofing is by manually typing the web address you need instead of relying on links.  You can also check if the link you want to access begins with ‘https://’ or has a lock symbol, suggesting it’s secure. 

3. Watch out for phishing scams 

There are lots of tips that we can give you regarding phishing precautions.  – check grammar and punctuation. Suspicious e-mails might include poor grammar or punctuation or might show an illogical flow of content.  – remember that established banks never ask you sensitive information via e-mail. Consider big red flags any e-mails that ask you to enter or verify personal details or bank/credit card information.  – pay special attention to alarming e-mail content and messages where you are told that one of your accounts has been hacked, that your account has expired or other extreme issues that may provoke panic. Do not take immediate action! – don’t fall for urgent deadlines either. This kind of e-mails usually leads the users to data harvesting websites, where sensitive personal or financial information are stolen.  – beware of shortened links. They don’t show the real name of a website, so they are a perfect way to trick users into clicking. Get used to always place your cursor on shortened links to see the target location. 

4. Use strong router credentials 

Make sure that not only your Wi-Fi password but also router credentials are changed. In these credentials are found by an attacker, they can be used to change your DNS servers to their malicious ones or to infect your router with malware. 

5. Make sure your company has a software update policy

A software update policy helps you seal potential access points for a man-in-the-middle attack because up-to-date systems include all current security patches for known issues. The same should be considered for any routers or IoT devices connected to your network. 

6.  Adopt a zero-trust security model 

Although it might seem a little too much, requiring your colleagues to authenticate themselves each time they connect to your network regardless of where they are will make it more difficult for hackers to pretend to be someone else. They would need to prove their identity before accessing the network in the first place.   Learn more about the zero-trust model and your organization will be more secure by default.

7. Prevent cookie stealing

Saving passwords on web browsers or storing credit card information on shopping websites might save you a bit of time, but it also leaves you more vulnerable to hackers. You should try to avoid storing sensitive information on websites and also get used to clear your cookies regularly. If you use Chrome, you can do this by accessing History > Clear Browsing History and ticking the checkbox “Cookies and other site data”. 

Heimdal™ Security can also help. Here’s how!  

As we have already seen, a man-in-the-middle attack can take various forms: IP, HTTPS or DNS Spoofing, SSL or e-mail hijacking, browser cookie theft or Wi-Fi eavesdropping.  Some of the Heimdal™ solutions are perfect for protecting your business from them: Heimdal™ Threat Prevention offers DNS and DoH security, plus a powerful and scalable Automated Patch Management system. Its DarkLayer Guard™ mitigates ransomware, next-gen attacks and data leakage. Its VectorN Detection™ tracks device to infrastructure communication and its Heimdal™ Patch & Asset Management​ feature closes vulnerabilities and deploys updates anywhere in the world. 

For paramount protection, you can combine it with Heimdal™ Next-Gen Antivirus & MDM, our antivirus solution with unparalleled threat intelligence, EDR, forensics and firewall integration.   

For your e-mail security, we have developed Heimdal™ Email Security. Heimdal™ Email Security can help you detect malware, and stop spam, malicious URLs and phishing with simple integration and highly customizable control. If you want to take one step further, Heimdal™ Email Fraud Prevention will make sure that no e-mails containing fraud attempts, business e-mail compromise or impersonation reach your inbox. 

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Wrapping up…

When trying to prevent a man-in-the-middle attack, there are three major aspects you must consider:

awareness & education. People are the ones who unknowingly click on bad links or use their login data on a compromised website, allowing hackers access to their information, so making sure that your colleagues and employees know the basic principles of preventing MITM attacks is essential. 

encryption & VPNs. Use encryption on all of your company’s devices and use VPNs whenever you connect to public networks, for extra protection. 

software update policy. Make sure that all your systems are up-to-date. Even a single point of failure can put your entire network in danger. 

Also, please remember that Heimdal™ Security always has your back and that our team is here to help you protect your home and your company against cyber threats and to create a cybersecurity culture to the benefit of anyone who wants to learn more about it.

Drop a line below if you have any comments, questions or suggestions – we are all ears and can’t wait to hear your thoughts!

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