If the page loads normally, the attacker knows the database is expecting 6 columns.
This is the "probe" part of the injection. The attacker is trying to determine the number of columns being returned by the original database query. If the page loads normally, the attacker knows
Scanners append strings like GoJB so that the security researcher can search the website's logs or the page's source code later to confirm that their input was successfully processed and reflected by the server. Summary of the Attack Flow If the page loads normally