The string you provided is a designed to discover the number of columns in a database table. Breakdown of the Payload
: This is likely a random string or a "signature" used by a vulnerability scanner (like Burp Suite or sqlmap) to track if the payload was successfully reflected in the application's response. {KEYWORD}) UNION ALL SELECT NULL,NULL,NULL,NULL,NULL-- ZkhD
An attacker (or security researcher) would send this payload to an application to see if it returns an error or a successful response. The string you provided is a designed to
For more in-depth technical guides, you can visit the Web Security Academy or community forums like Medium . {KEYWORD}) UNION ALL SELECT NULL,NULL,NULL,NULL,NULL-- ZkhD
: This is a comment indicator that tells the database to ignore the rest of the original query that follows.
