Facebook Phishing Attack: A Write-up and PHP Code Analysis
Part 5: Defensive Strategies – How to Neutralize post.php Attacks
This is the core exfiltration method. It appends the stolen credentials to a text file. The LOCK_EX flag prevents simultaneous writes from corrupting the file if multiple victims hit the script at once.
Modern PHP frameworks (Laravel, Symfony) include built-in CSRF protection. While this does not directly prevent phishing (because the attacker controls the form), it does prevent cross-site request forgery. Ironically, most post.php scripts do not use any framework—they are raw, procedural PHP.
The link led to a fake Facebook login page hosted on a compromised university .edu domain. The post.php script was hidden in /blog/wp-includes/post.php . Over 6,000 accounts were compromised in 48 hours because:
- APWG Phishing Activity Trends Report, Q4 2024.
- Facebook Transparency Report – Phishing and Malware.
- MITRE ATT&CK Technique T1566 (Phishing) & T1059 (Command and Scripting Interpreter).
- PHP.net – Security of
mail()and remote file access. - YARA Project – Rule writing guide.
False positive risk:
Legitimate login handlers using post.php ? Extremely rare. Most apps use login.php or auth.php . If found, typically malicious.