If you found this in your website logs, someone is [2]. If you are a developer, this is a reminder to use parameterized queries (prepared statements) to ensure user input is never treated as executable code [2, 6].
: The attacker uses NULL to match the number of columns in the original table [3]. The random string ( 'qbqvq'||... ) is a "fingerprint" used to confirm the injection worked by seeing if that specific text appears on the page [5]. If you found this in your website logs, someone is [2]
: This is a comment marker that tells the database to ignore the rest of the legitimate code, preventing errors [1, 3]. What This Means for You preventing errors [1