Watcher is a runtime passive-analysis tool for HTTP-based Web applications. Watcher provides pen-testers hot-spot detection for vulnerabilities, developers quick sanity checks, and auditors PCI compliance auditing. It looks for issues related to mashups, user-controlled payloads, cookies, comments, HTTP headers, SSL, Flash, Silverlight, referrer leaks, information disclosure, Unicode, and more.

Major Features:

1. passive detection of security, privacy, and PCI compliance issues in HTTP, HTML, Javascript, and CSS
2. Works seamlessly with complex Web 2.0 applications while you drive the Web browser
3. non-intrusive, will not raise alarms or damage production sites
4. Real-time analysis and reporting - findings are reported as they’re found, exportable to XML
5. configurable domains with wildcard support
6. extensible framework for adding new checks