A Man-in-the-Middle (MITM) attack is a type of cyberattack where a malicious actor inserts themselves between two parties that are communicating, such as a user and a website. The attacker intercepts the traffic going between the user and website, and can eavesdrop on or even alter the communication.
Example: Imagine you are writing letters back and forth with your bank. You put your letters in the mailbox and the bank receives them and writes back.
In a MITM attack, it’s like someone sneakily intercepts your letters, opens and reads them, then reseals the envelopes and passes them on to the bank. They could even write fake letters and send them to the bank, pretending to be you. Meanwhile they are collecting sensitive info from your real letters, like your account number and balance.
How it works on the web:
- When you connect to a website, your web traffic goes through a series of routers and servers before reaching the destination website.
- In an MITM attack, the attacker gains access to an intermediate point in this chain, like an unsecured WiFi router, and can intercept your traffic.
- They use tools to read any unencrypted data you are sending the website, like login credentials. They can also alter the responses coming back from the website.
- For example, when you connect to your bank’s website to login, the MITM could capture your username and password, then pass through a fake website that looks like your bank’s login page to steal even more info.
Defenses against MITM:
- Always check that the padlock icon is present and the URL starts with “https” to ensure an encrypted connection on sensitive sites
- Avoid connecting to public WiFi networks or use a VPN when on untrusted networks
- Enable two-factor authentication on important accounts so even a stolen password isn’t enough
So in summary, an MITM attack allows bad actors to secretly insert themselves in the middle of your communication with a website in order to steal data or manipulate what you see. Vigilance around the security of your connection and accounts is key to preventing them.