Watering Hole Attack - Injected Script on Legit Site

Darshan Thummar@Mighty

•updated Jun 11, 2026•0•0•1

This rule detects a potential watering hole attack where a legitimate website has been injected with a script that attempts to load content from an IP address. Specifically, it looks for HTTP responses (flow:to_client) containing '<script src=' followed by a URL where the source is an IP address (e.g., 'src="http://1.2.3.4/script.js"'). This technique is often used by attackers to compromise visitors of a trusted site by redirecting them to malicious content or exploiting vulnerabilities.