{keyword} Union All Select Null,null,null,null,null,null,null,null-- Ppsq Info

Once an attacker knows there are 8 columns, they can replace the NULL values with commands to extract sensitive data, such as usernames, passwords, or database versions. SQL injection UNION attacks | Web Security Academy

: If the number of NULL values does not match the original query's column count, the server usually returns an error (like a 500 Internal Server Error). Once an attacker knows there are 8 columns,

The string you provided is a classic payload. It is not a feature of a specific software product but rather a technique used by security researchers and attackers to probe databases for vulnerabilities. Purpose of the Payload such as usernames