A man-in-the-middle (MITM) attack is an attack in which an attacker intercepts communications between two parties and alters or eavesdrops on the messages without either party being aware of the attack. This can compromise the confidentiality, integrity, and availability of data and can be highly damaging if not detected and prevented in time.
Here are some techniques that can be used to detect MITM attacks:
1. Packet analysis: Network administrators can monitor network traffic through the use of tools that analyze packets, such as Wireshark. If a third party is intercepting traffic, abnormalities in packet sequences, TTL values, and packet sizes can be identified.
1. Trusted certificates validation: Most mitm attacks rely on creating their own self-signed certificates. When certificates do not match the expected trusted certificates, it could be a sign that a man-in-the-middle attack is in place.
1. DNS resolution validation: An attacker may use DNS spoofing to redirect traffic to a fake website or IP. In this regard, validating DNS resolution can detect a possible attack. Some web browsers, such as Chrome, have DNS over HTTPS (DoH) enabled by default, making it harder for malicious actors to spoof DNS.
1. SSL/TLS analysis: MITM attackers often attempt to intercept traffic covered by SSL/TLS by acting as a proxy, in which case they create their own fake SSL certificates. Certificates can be analyzed to ensure they are valid and originating from trusted authorities.
1. Out-of-band communication: Communicating with parties involved in the communication using a different mode to verify the information sent can serve as a countermeasure for man-in-the-middle attacks.
1. Firewall setup: Proper setup of a firewall can limit the number of different paths an attacker can take to execute a man-in-the-middle attack, some devices can also detect and block specific attacks.
Overall, mitigation of man-in-the-middle attacks requires combined efforts of technology, awareness and of course, a well-informed security professional who can balance the security risk, weigh security vs usability and formulate an acceptable solution.
