How to Stop a Sneaky Man-in-the-Middle

The CyberWhite guide explains how man-in-the-middle (MITM) attacks let crooks slip between users and online services to pinch log-ins, card details and other goodies. It recaps headline-grabbing examples (Equifax, Lenovo Superfish, DigiNotar) and outlines favourite tactics: rogue public-Wi-Fi, mDNS/DNS spoofing, ARP games and look-alike access points. Defence boils down to five best-practice buckets: encrypt everything (HTTPS, HSTS, certificate pinning), secure the network (VPN, segmentation, DNSSEC/DoH), authenticate and validate (mutual TLS, MFA, key rotation), monitor endpoints and traffic (IDS/IPS, EDR, certificate-mismatch alerts) and educate users and developers (heed cert warnings, never disable validation, bake SAST/DAST into the pipeline). The piece finishes with an advertorial nod to Specops Password Policy for hardened Active Directory creds.

Ever tried sharing gossip in a pub only to find the bloke at the next table is recording every word? That’s a man-in-the-middle (MITM) attack just swap the pub for Wi-Fi and the bloke for a hoodie-wearing hacker.

1. Know the battlefield
Crooks love crowded hotspots—airports, cafés, hotel lobbies—where they set up evil twins of “FreeAirportWiFi” and wait for your phone to auto-connect. Once you’re on their network, it’s open season on passwords, credit-card data and cat memes.
2. The tricks of the trade
• DNS & mDNS spoofing – reroutes your browser to a fake site faster than you can say “padlock icon”.
• ARP spoofing – hijacks local traffic by pretending to be the gateway.
• Wi-Fi name cloning – “Hilton_Guest” becomes “HiIton_Guest” (spot the sneaky capital ‘i’).
3. Five ways to ruin a hacker’s day
1. Encrypt everything – Force HTTPS, slap on HSTS and pin those certs like there’s no tomorrow.
2. Lock down the network – Use a proper VPN on public Wi-Fi, segment your LAN and sign your DNS (DNSSEC/DoH).
3. Double-check identities – Mutual TLS plus MFA means the hacker needs more than your dog’s name to break in.
4. Watch the wire – IDS/IPS for odd TLS handshakes; EDR to spot rogue proxies and ARP shenanigans.
5. Train the humans – “Certificate error? Click Cancel, not Continue.” Developers: never, ever disable cert validation—yes, we’re looking at you.
4. Bonus: password hygiene

Weak or breached passwords turn intercepted traffic into easy pickings. A policy tool that bans rubbish passphrases (think “P@ssw0rd123”) is cheaper than cleaning up an account-takeover mess.