Null,null,null,null,null# — {keyword}') Union All Select

This payload is a classic example of , specifically used during the initial discovery phase of an attack to determine the structure of a database query. Payload Breakdown

The string "{KEYWORD}') UNION ALL SELECT NULL,NULL,NULL,NULL,NULL#" consists of several distinct components: {KEYWORD}') UNION ALL SELECT NULL,NULL,NULL,NULL,NULL#

Understanding SQL Injection: Testing Techniques and Tools for This payload is a classic example of ,