performing-adversary-in-the-middle-phishing-detection

name	performing-adversary-in-the-middle-phishing-detection
description	Detect and respond to Adversary-in-the-Middle (AiTM) phishing attacks that use reverse proxy kits like EvilProxy, Evilginx, and Tycoon 2FA to bypass MFA and steal session tokens.
domain	cybersecurity
subdomain	phishing-defense
tags	["aitm","evilproxy","evilginx","phishing","mfa-bypass","session-hijacking","reverse-proxy","credential-theft"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["PR.AT-01","DE.CM-09","RS.CO-02","DE.AE-02"]
mitre_attack	["T1566","T1598","T1534","T1036","T1003"]
source	https://github.com/mukul975/Anthropic-Cybersecurity-Skills
source_commit	04450304b12645cb2b974ab96d28c0664758a88d

Performing Adversary-in-the-Middle Phishing Detection

Overview

Adversary-in-the-Middle (AiTM) phishing attacks use reverse-proxy infrastructure to sit between the victim and the legitimate authentication service, intercepting both credentials and session cookies in real time. This allows attackers to bypass multi-factor authentication (MFA). The most prevalent PhaaS kits in 2025 include Tycoon 2FA, Sneaky 2FA, EvilProxy, and Evilginx. Over 1 million PhaaS attacks were detected in January-February 2025 alone. These attacks have evolved from QR codes to HTML attachments and SVG files for link distribution.

When to Use

• When conducting security assessments that involve performing adversary in the middle phishing detection
• When following incident response procedures for related security events
• When performing scheduled security testing or auditing activities
• When validating security controls through hands-on testing

Prerequisites

• Azure AD / Entra ID Conditional Access policies
• SIEM with authentication log ingestion (Azure AD sign-in logs)
• Web proxy with SSL inspection and URL categorization
• Endpoint Detection and Response (EDR) solution
• FIDO2/phishing-resistant MFA capability

Key Concepts

How AiTM Works

1. Victim receives phishing email with link to attacker-controlled domain
2. Attacker domain runs reverse proxy that mirrors legitimate login page
3. Victim enters credentials on proxied page; credentials captured in transit
4. Reverse proxy forwards credentials to real authentication service
5. MFA challenge sent to victim; victim completes MFA on proxied page
6. Attacker captures session cookie returned by legitimate service
7. Attacker replays session cookie to access victim's account without MFA

Major AiTM Kits (2025)

Kit	Type	Primary Targets	Evasion
Tycoon 2FA	PhaaS	Microsoft 365, Google	CAPTCHA, Cloudflare turnstile
EvilProxy	PhaaS	Microsoft 365, Google, Okta	Random URLs, IP rotation
Evilginx	Open-source	Any web application	Custom phishlets
Sneaky 2FA	PhaaS	Microsoft 365	Anti-bot checks
NakedPages	PhaaS