Trappa detects a CGI scan and sends an alert message to syslog with the attackers IP+Web Browser. Works by installing decoy CGI scripts in the cgi-bin directory.
You can download it from the following link: https://packetstormsecurity.com/files/download/17803/trappa.tar.gz
Source: https://packetstormsecurity.com/files/17803/trappa.tar.gz.html