How to Tell If You're Being Hit by a Man-in-the-Middle Attack
Think of a "Man-in-the-Middle" (MitM) attack like an unwelcome eavesdropper secretly listening in on your private conversations. In the digital world, this means someone is intercepting your internet traffic, potentially seeing sensitive information you send and receive.
If you suspect a MitM attack, stop using the internet connection immediately and switch to a trusted network, like your mobile data, to protect your information.
What is a Man-in-the-Middle (MitM) Attack?
A Man-in-the-Middle attack happens when a cyber attacker secretly inserts themselves between your device (like your laptop or phone) and the website or service you're trying to connect to. They can then spy on your activity, steal your data, or even change the information you're sending.
Watch for Unusual Browser Warnings
Your web browser is often the first line of defence. If a website's security certificate has been tampered with or is fake, your browser will usually display a prominent warning. Don't ignore these!
- Look for messages like 'Your connection is not private', 'This site is not secure', or 'Potential Security Risk Ahead'.
- Check the address bar for a crossed-out padlock icon or a red warning triangle.
Examine Website Certificates Closely
Every secure website uses a 'digital certificate' to prove its identity. If an attacker is intercepting your connection, they might try to use a fake or modified certificate. You can check a site's certificate in your browser.
- Click the padlock icon in your browser's address bar.
- Select 'Connection is secure' or 'Certificate' to view details.
- Verify that the certificate is issued to the correct website and by a reputable certificate authority (like DigiCert or Let's Encrypt).
- Look for unusual issue dates, expiry dates, or names that don't match the website you're visiting.
Notice Unexpected Website Behaviour or Appearances
Attackers can sometimes modify web pages as they pass through their interception point. This might lead to strange visual cues or unexpected requests for information.
- Web pages loading incorrectly or unusually slowly.
- Strange pop-ups asking for personal information that don't seem like part of the legitimate website.
- Links that redirect to unexpected or incorrect addresses when you hover over them (check the bottom left of your browser window).
Be Wary of Public Wi-Fi Networks
Public Wi-Fi, especially those that don't require a password, are common hunting grounds for MitM attackers. It's much easier for an attacker to set up a rogue Wi-Fi hotspot and intercept traffic.
- Avoid performing sensitive activities like online banking or shopping on public Wi-Fi.
- Always use a Virtual Private Network (VPN) when connecting to public Wi-Fi networks to encrypt your traffic.
- Be suspicious of Wi-Fi network names that look similar but not identical to the legitimate network (e.g., 'Free_Cafe_WiFi' instead of 'Cafe_Free_WiFi').
Key takeaway
Spotting a Man-in-the-Middle attack often comes down to paying close attention to your browser