SSTI payload execution chain from web application process to shell/RCE

This rule monitors for potential Server-Side Template Injection (SSTI) exploitation by detecting web application processes (such as Java, Python, or Web Server binaries) that initiate child processes (such as shell interpreters or script engines) while their command line contains common SSTI markers or exploitation patterns like '{{7*7}}', 'subprocess.Popen', or 'java.lang.Runtime'. This indicates an attacker has successfully escalated from template injection to remote code execution.