What is a Man-in-the-Middle Attack?

A man-in-the-middle (MITM) attack, also known as an eavesdropping attack, is a malicious theft of information orchestrated by a hacker looking to intercept sensitive data. Usually, this type of attack occurs as information is transferred over a compromised network by a computer, smartphone, or another connected device. 

These attacks are especially relevant for small to medium-sized businesses as most MITM attacks are targeted at organizations that don’t have the money for expensive cybersecurity solutions. While MITM attacks can be devastating, they are more straightforward to prevent than other cyber attacks and can be avoided with a combination of awareness, precaution, and cyber insurance.

Types of Man-in-the-Middle Attacks

Typically, MITM attacks are initiated through an unsecured network, malware injected directly into a computer, or DNS spoofing.

With traditional MITM attacks, the hacker gains access to an unsecured Wi-Fi router. These types of connections are common in public areas with free Wi-Fi hotspots such as your local coffee shop, or even in some people’s homes if they haven’t sufficiently protected their networks. Attackers can initiate this attack by scanning the router for specific vulnerabilities such as a weak password. Once the hacker identifies a vulnerability in the network, they can deploy malware to intercept the victim’s transmitted data or reroute it to their own fake network. This can include payment information, login credentials, personal passwords, customer information, etc. 

Another form of MITM attacks is malware attacks, specifically man-in-the-browser attacks. These attacks differ from traditional MITM attacks as they involve malicious software or malware that is injected directly into the victim’s device. This malware, often referred to as a “Trojan Horse,” infects the computer’s OS or application browser and monitors transactions that take place on the browser. For example, if an infected computer owner enters their payment information with any online retailer, the malware will record the website and transmit the data to the hacker. This attack can potentially be more harmful than the traditional MITM attack as an active piece of malware can sit unnoticed in an infected computer unless the victim is actively searching to see if their communications are being intercepted.

One of the most difficult forms of MITM attacks to deal with is those initiated by DNS spoofing. These attacks have become incredibly popular in the last few years and demand constant awareness. In general, Domain Name Server or DNS spoofing is when a hacker redirects a user onto a fake website rather than the intended one. The hacker can set up this attack by purchasing a similar URL to a legitimate website and disguising their fraudulent site as the original. These mock websites can be incredibly convincing and have, on occasion, even fooled employees of the legitimate business. Finally, the hacker can use a DNS spoofer to redirect all DNS requests to his own fraudulent website. Once the user is on the website, the hacker can intercept any data transmitted.

How to Prevent Man-in-the-Middle Attacks‍

To protect your business against traditional MITM attacks:

1. Never use a public Wi-Fi router directly when accessing sensitive business information. Free unsecured networks such as those at your local coffee shop or library are a gold mine for hackers looking to intercept data. 
2. If you must use an unsecured network, a VPN or virtual private network can be an excellent tool to help shield and encrypt the data you send and receive. 
3. Update to the latest versions of secure web browsers such as Chrome or Safari.
4. Pay attention to browser alerts reporting that a website is unsecured.
5. Be sure that your Wi-Fi networks are secure. Update default usernames and passwords on your routers and all connected devices to strong, unique passwords. 
   

To protect your business from man-in-the-browser attacks:

1. Take precautionary steps to protect your and your employees’ devices from malware.
2. Install comprehensive malware and antivirus software.
3. Be alert when browsing on unknown websites and especially wary if you’re downloading any software or media files.
4. If you detect any suspicious software on your device, scan it with an anti-malware software.
5. Be cognizant of what links and emails you click on and open! Always check the sender’s email address to verify that the email is from the correct person. If you’re not expecting an email with an attachment, don’t open and confirm with that person via another method.
6. Regularly check your company’s banking activity to quickly spot an irregularity.
   

To protect your business from DNS spoofing:

1. Install DNSSEC extensions. DNSSEC is short for Domain Name System Security Extensions, which help verify DNS origin. These extensions digitally sign information to verify and authenticate data. 
2. Actively monitor DNS data for irregularities.
   

In addition to taking these steps, ensure that your staff are well informed and equipped to tackle potential breaches. Establish a security training program that keeps security top-of-mind and actively tests your employees’ knowledge. 

Conclusion

By educating yourself on the different types of MITM attacks and steps to prevent them, you can take measures to ensure that your business stays cybersecure. As the saying goes, “prevention is better than a cure,” and with most forms of cyber attacks, proactively protecting your business can prove more effective than having to recover from a damaging attack!