import re

def is_malicious_input(input_text: str) -> bool:
    # Example: Basic regex for common injection attempts
    if re.search(r"(\<script\>|\bjavascript:)", input_text, re.IGNORECASE):
        return True
    # Add more sophisticated checks for keywords, toxicity scores, etc.
    return False

user_input = "<script>alert('XSS')</script>"
if is_malicious_input(user_input):
    print("Input rejected: Potential security risk detected.")
else:
    # Proceed with LLM interaction
    pass