A man-in-the-middle (MitM) attack is one of the most insidious forms of hacking. It works by covertly inserting a malicious actor between two parties communicating online. The victims believe their connection is private, but in reality the attacker has full access to intercept sensitive data flowing between them.
MitM attacks cost businesses and individuals billions per year according to cybersecurity firm Coveware. And the prevalence of these attacks is only growing as more of our daily lives move online.
But knowledge is power when it comes to defending yourself. Let‘s peel back the layers on how MitM attacks work, real-world examples, and most importantly how you can stay safe.
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Diving Into the Techniques Behind MitM Attacks
MitM attacks only work when three conditions are met:
- Two victims try to communicate securely
- The attacker gains privileged access to the conversation
- Neither party detects the attacker‘s presence
Various clever techniques allow hackers to create this dangerous digital sandwich:
Session Hijacking
Like a thief sneaking through an open window, the attacker takes over an active logged-in session. They can access accounts and data without cracking encryption.
Some methods include:
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Sidejacking: Using packet sniffing tools to steal session cookies, which store login credentials.
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Wi-Fi snooping: Intercepting weakly encrypted Wi-Fi packets transmitting session cookie data.
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Brute force attacks: Guessing session IDs and passwords through automated rapid-fire attempts.
Phishing
Phishing lures victims into handing over login credentials themselves through deceptive emails, texts, calls and fake websites. Users are tricked into believing these sources are legitimate.
Some phishing techniques include:
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Impersonation: Spoofing the sender email or website to appear as a trusted source.
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Urgency: Creating a false sense of urgency to click links and provide info.
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Fear: Threatening account suspension, legal action or other repercussions if demands are not met.
Evil Twin Attacks
Evil twin networks exploit the tendency to automatically connect to any open Wi-Fi. By creating a fake cloned network, the attacker routes all of the victim‘s communications through their controlled connection.
This attack is possible because:
- Public Wi-Fi often has no password or encryption
- Network names offer no identity verification
- Users overlook SSL warnings when connecting
DNS Cache Poisoning
Also called DNS spoofing, this attack corrupts Domain Name System caches. DNS translates human-readable domains into machine-readable IP addresses.
Cache poisoning exploits the fact that:
- DNS caches assembled from multiple sources
- Cache entries expire after a fixed time
- Individual IP/domain pairs are not cryptographically signed
By inserting fake IP address results, the attacker redirects traffic to clone sites they control.
SSL Stripping
Many sites use HTTPS encryption to protect communications. SSL stripping bypasses this by:
- Intercepting traffic and downgrading HTTPS to HTTP
- Reading unencrypted data
- Forwarding traffic to the original server
Users may see SSL padlock icons and believe their session is secure, but it has already been compromised.
IP Address Spoofing
Because TCP/IP traffic relies on source and destination IP addresses, hackers can spoof their origin address. This allows them to:
- Impersonate a trusted host
- Intercept routing data
- Evade detection
It exploits the inherent trust of IP addresses before additional identity verification occurs.
Real-World MitM Catastrophes
To appreciate the real-life impacts of MitM attacks, let‘s examine some case studies:
The Uber Breach
In 2016, hackers used phishing to gain access to an employee‘s Uber account. From there, they were able to obtain credentials to access Uber‘s GitHub code repositories, user database, and compute infrastructure.
In total, data on 57 million riders and drivers was compromised. Uber paid $148 million to settle legal and regulatory actions related to the breach.
The Juniper Networks Attack
In 2015, sophisticated attackers altered code signing certificates on Juniper‘s NetScreen firewalls. This allowed them to remotely install spyware that decrypted VPN connections, giving access to sensitive data.
The attackers also further compromised certificate authorities and key management systems to cover their tracks. The campaign was likely carried out by a nation-state.
The Lenovo Superfish Scandal
For several months starting in 2014, Lenovo preinstalled adware called Superfish on some consumer laptop models. To serve targeted ads, Superfish installed fake root certificates that let them intercept and decrypt all user browser traffic – even HTTPS encrypted connections.
When discovered, this massive violation of user privacy resulted in public outcry, Congressional investigations, and numerous class action lawsuits. Lenovo‘s brand reputation took a major hit.
The Equifax Breach
In 2017, attackers exploited a vulnerable open-source framework called Apache Struts to breach Equifax‘s systems. They managed to steal personal information on 147 million consumers, including social security numbers, birthdates, addresses, and some driver‘s license numbers.
The cost of the data breach to Equifax has been estimated at $1.4 billion when accounting for legal fees, federal fines, and loss of revenue.
Securing Yourself from MitM Attacks
While individuals may feel powerless against sophisticated MitM attacks, there are simple precautions you can take:
Use a VPN
A VPN encrypts all traffic leaving your device, preventing the data interception and redirection that enables MitM attacks. Prioritize VPNs offering "perfect forward secrecy" ensuring keys cannot be compromised.
Verify Sites Use HTTPS
Look for the green padlock icon and https:// in the URL bar. The ‘S‘ means TLS/SSL encryption is protecting your communications and transactions. If you only see http://, leave the site immediately.
Update All Software
Patching security vulnerabilities through prompt software and operating system updates foils many MitM attack vectors. Turn on automatic updates when possible and check periodically for new patches.
Avoid Public Wi-Fi for Sensitive Tasks
Do not access financial accounts, work email or provide personal info over public Wi-Fi. Use cellular data or your phone‘s Wi-Fi hotspot when possible. Or ensure your traffic is routed through a trustworthy VPN.
Enable Multi-Factor Authentication
MFA requires secondary proof of identity like a text code or biometric scan when logging into accounts. This provides an extra layer of protection against phishing and stolen credentials being used by attackers.
Monitor Accounts for Unusual Activity
Routinely review your account logs and statements to check for any unauthorized access, unknown devices or transactions not made by you. Report anything suspicious immediately.
Run Antivirus Software
Make sure all of your devices have updated antivirus software installed. This provides real-time monitoring for known threats. Pair antivirus with good browsing habits and firewalls for layered security.
For organizations, additional protections like intrusion detection systems, network segmentation, and routine audits are critical to avoid becoming the next high-profile MitM attack victim.
Final Thoughts
MitM attacks may seem like futuristic cybercrimes, but weak points in trusted communication systems make them possible and even easy to execute for skilled hackers.
The good news is individuals are not helpless against MitM attacks. Empower yourself through education, smart habits online, and using the right tools. Encryption is your ally.
No solution is 100% foolproof. But a little added vigilance in navigating today‘s digital world goes a long way. Pay attention to signs of tampering, critically evaluate requests for your data, and follow best practices to minimize risk.
With vigilance and savvy, you can take control of your security footprint online and thwart MitM attacks that try to victimize the vulnerable and unaware.
