Select Null,null,null,null,null,null,null,null-- Mxyc | {keyword}') Union All

Here is a look into what that string is designed to do and why it’s a fundamental concept in web security. What is this string?

The text ') UNION ALL SELECT NULL,NULL...-- is a malicious payload used to test for vulnerabilities in a database. Here is a look into what that string

: Attackers use NULL to figure out exactly how many columns the original database table has. If the number of NULL s matches the columns, the page loads; if not, it crashes. the page loads