XSSYA is a python tool that attempts malicious payloads for bypassing web application firewalls.
You can download it from the following link: https://packetstormsecurity.com/files/download/130764/XSSYA-V-2.0.zip
Source: https://packetstormsecurity.com/files/130764/XSSYA-Cross-Site-Scripting-Scanner-2.0.html