Understanding Man-In-The-Middle (MITM) Attacks
MITM attacks occur when a malicious actor inserts themselves into a conversation between two parties to eavesdrop or manipulate the data being exchanged.
The most dangerous part of a MITM attack is that the victim often has no idea it is happening; the internet appears to be working normally while their data is being stolen.
How ARP Spoofing Works
In a local network, devices use ARP (Address Resolution Protocol) to link IP addresses to physical MAC addresses. An attacker can send fake ARP messages to the router, claiming that the attacker's MAC address is actually the victim's IP.
Once the router is fooled, it sends all of the victim's traffic to the attacker first. The attacker then forwards it to the real destination so the connection doesn't drop.
Common MITM Tools in Kali
Bettercap and Ettercap are the industry standards for MITM attacks. These tools can automate ARP spoofing, perform DNS poisoning (redirecting a user to a fake website), and sniff passwords from unencrypted traffic.
Defense Tip: Using HTTPS (SSL/TLS) encrypts the data, making it unreadable to the attacker even if they successfully intercept the packets.
Types of MITM Attacks
Beyond ARP spoofing, attackers use DNS spoofing to send users to fraudulent login pages, or Session Hijacking to steal "cookies" and take over a user's logged-in account without needing a password.
MITM Prevention Checklist
- Always use a VPN on public WiFi.
- Ensure websites use HTTPS (look for the padlock).
- Use Static ARP entries for critical servers.
- Implement DHCP Snooping on corporate switches.
- Use Multi-Factor Authentication (MFA) to prevent session takeover.
The Bottom Line
MITM attacks highlight the danger of trusting local networks. Encryption is the only absolute defense against the "man in the middle."
