The string is designed to trick a website’s search bar or login field into running extra commands it wasn't supposed to.
: The attacker starts with a value that likely doesn't exist (like a negative ID number). This "breaks" the original intended query, forcing the database to ignore the real results and display the attacker's fake results instead. -9825 UNION ALL SELECT 34,34,34,34,34,34,34,34,34,34#
: The attacker is playing a guessing game. A UNION attack only works if both queries have the exact same number of columns . By repeating "34," the attacker is testing if the database table has 10 columns. If the page loads without an error, they’ve found the "shape" of the table. The string is designed to trick a website’s