{keyword}' Union All Select Null,null,null,null,null,null,null,null-- Jynz -

This specific string is designed to be appended to a vulnerable input field (the {KEYWORD} in your example) to probe the database structure: : Closes the original string literal in the SQL query.

: Attempts to select 8 columns of "null" data. This specific string is designed to be appended

NULL is used because it is compatible with almost any data type (string, integer, date, etc.), ensuring the query won't fail due to data type mismatches. : This is a SQL comment, which tells

: This is a SQL comment, which tells the database to ignore the rest of the original, legitimate query that follows. The Goal of the Attack : This is a SQL comment

The payload you provided, ' UNION ALL SELECT NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL-- , is a common pattern used in to determine the number of columns returned by an original database query. What this Payload Does