: These are "dummy" values used to match the number of columns in the original database table. If the column counts don't match, the attack fails, so hackers often guess the number of columns this way.
If you found this in your website logs, email subjects, or contact forms, someone (or more likely an automated bot) is . They are looking for "entry points" where user input isn't properly cleaned before being sent to the database. How to protect your data
Never trust user input. Use allow-lists to ensure only expected data types (like numbers or plain text) are processed.
: This is a string concatenation. The attacker is trying to print a unique string (like a "fingerprint") to the screen. If "qbqvqoQMUFBfpihqqbqq" appears on the webpage, the attacker knows the site is vulnerable.
: This is a comment operator in SQL. It tells the database to ignore the rest of the legitimate code that follows, effectively neutralizing any security checks at the end of the original query. Why you might be seeing this
: This command tells the database to combine the results of the original query with a new, forged query.
: This is likely a placeholder for a legitimate search term or ID used by an application.
The text you provided is a classic example of a payload. Specifically, it uses the UNION ALL SELECT statement to attempt to trick a database into revealing unauthorized information or appending malicious data to a legitimate query. What is happening in this string?
