All Select Null,null,null,null,null-- Bwmv — {keyword}' Union

: This is the core of the attack. It tells the database to append the results of a second query to the results of the first one.

: This is likely a random "cache-buster" or unique identifier used by automated security scanners (like Burp Suite or Acunetix) to track which specific payload triggered a response. Why you are seeing this

: A WAF can automatically block requests containing common injection patterns like UNION SELECT . {KEYWORD}' UNION ALL SELECT NULL,NULL,NULL,NULL,NULL-- bWmV

: The attacker is trying to determine how many columns the original database table has. If the number of NULL values doesn't match the number of columns in the original query, the database will return an error. By adding or removing NULL s, an attacker can find the exact table structure.

: This is a SQL comment. It tells the database to ignore everything that follows it, effectively neutralizing the rest of the original, legitimate code. : This is the core of the attack

: Always filter and validate data coming from users.

: This ensures the database treats input as data only, never as executable code. Why you are seeing this : A WAF

The string you provided, '{KEYWORD}' UNION ALL SELECT NULL,NULL,NULL,NULL,NULL-- bWmV , is a classic example of a used for database exploitation and security testing. What this string does