Select Null,null,null,null-- Uizf — {keyword} Union All

: This command tells the database to combine the results of the original query with a new "injected" query.

: This is a SQL comment symbol. It tells the database to ignore the rest of the original, legitimate query, effectively "breaking" the intended logic to execute the injected code. {KEYWORD} UNION ALL SELECT NULL,NULL,NULL,NULL-- Uizf

: Confirm that the application is vulnerable to SQL injection. : This command tells the database to combine

This string is a classic example of a , specifically a Union-Based SQLi attack . It is used by attackers to test for vulnerabilities or extract data from a database. Breakdown of the Payload {KEYWORD} UNION ALL SELECT NULL,NULL,NULL,NULL-- Uizf

: In some cases, these injections can be used to log in without a valid password.