Null,null,null,null,null,null-- Gojb - {keyword} Union All Select

If the page returns an error (like "The used SELECT statements have a different number of columns"), the attacker will try again with five or seven NULL values until the error disappears. 4. -- (The Comment) In SQL, double-dashes signify the start of a comment.

: For a UNION to work, the second query must have the exact same number of columns as the first query. 3. SELECT NULL,NULL,NULL,NULL,NULL,NULL

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 returns an error (like "The

: This "comments out" the rest of the original SQL query written by the developers.

If the page loads normally, the attacker knows the database is expecting 6 columns. : For a UNION to work, the second

This is a SQL operator used to combine the result sets of two or more SELECT statements into a single result set.

: A website takes user input and places it directly into a SQL query without "cleaning" it first. The attacker is trying to determine the number

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